Baking brownies from the inside out

brownies. They're delicious but polarizing. Some like the soft and delicious center. Others like the edges, which are hard and tar kind of thing you might ask your doctor about. But if you're really into that, they actually make a pan with this crazy shape which cooks the entire brownie all edges. And I've always wondered if there's an all edge pan, why isn't there a no edge pan? It seems like the kind of thing that should exist, but it doesn't. What would it even look like? a brownie sphere floating the brownie in midair or a four-dimensional hyper brownie tesseract pan. I decided it's time to find out. And going into this project, I thought it wasn't going to be that bad. Like, how hard could it be to make a brownie pan? But it turned out to be a lot deeper rabbit hole than I was expecting. There was so much machining and baking. Then somehow electronics and software got involved, and I spent way too much time trying to impress my wife. But in the end, we have some pans unlike anything you've ever seen. So, join me on my quest to find out what would an edgeless pan even look like. The first thing we got to do is get on the same page about what a brownie edge even is. My wife thought I meant something like the edges of a cube, but that's not quite what I'm talking about. I think a better term would be the brownie boundary. Basically, the outer surface of the brownie, especially where it's touching the pan, which tends to be the chewier, tough part. But I think if we started asking for the boundary of the brownies, people would probably think there's something wrong with you. So, we're just going to call them edges. And the reason the edges are tougher is because of heat transfer. When you put brownies in the oven, it's super hot and they're cold. Heat energy flows from hot to cold until eventually they reach the same temperature. But inside the brownie, things take time. The batter touching the pan heats up first as the energy slowly migrates towards the center. By the time the center gets hot, the outside has been roasting for 10 or 20 minutes, giving that chewy, hard, edgel-like characteristic, and that all explains a lot. But there's still another subtle effect going on. Imagine we had a bit of brownie between two plates. It would heat up extra fast and get burned. And the corner of the pan is very similar. We have energy coming in from two sides, which heats up this area faster, making the corners of the pan the most overcooked parts. So, as is usually the case, my wife is right. The brownie edges are the edge of a cube. Which leads the obvious question. What if we made a pan with no corners? It should be easy. A cube without corners is a sphere. So, let's see if it works. Here it is. And it is so cute. Brownies expand when they're cooking, and I really don't want this thing blowing apart, which is why there's these screws. Having to bolt your brownie pan together isn't the most userfriendly design, but it's a prototype. You fill it through this tapered hole in the top, which perfectly fits a catheter syringe. I think a suppository syringe would be more appropriate, but this is just what I had. Let's see if it works. I don't think the batter agreed with the sphere. I think it may have overfilled this a little bit, but it's good. It means the brownie totally filled the sphere, which is what we're going for. I brought the wife in. She's one of the foremost brownie experts in the world. She got the Girl Scout brownie badge. Before that, she literally was a brownie and she thinks they taste good. So, we're going to get her opinion on how good these things are. Are you ready to taste the future? I'm ready to taste a brownie. I don't know if this brownie is one you would look forward to. All right, so I've got it underneath here. That's a small brownie. I like a hearty portion of brownie. You understand what's going on here. Well, there's no edges. Exactly. No edges. I wanted it to cook midair. I thought about that, but the biggest browning you could cook midair would be like a little drop. But let's get this open. I don't want to like just rip the Oh, smells like a brownie. I think it smells kind of weird. Take a little nibble. Make sure you get all over all 10,000 buds. Did that seem like the center of a brownie or the edge of a brownie? Pretty sentry. Oh, yeah. Yeah, that's soft. It's 1 to 10. Five. It's fast. I was thinking about it while I was eating it. You know, cook the brownie. There really isn't any difference at the edge. You just don't have that brownie texture. It's like a cake, not a brownie. It looks crusty, but it's not. E. It's neat. Novelty. Good for portion control, but not much else. I think the cake pop pan is kind of an

interesting novelty, but it's not even really a brownie pan. But it's all good because I have another idea. The center of the brownies takes a long time to cook because heat flows very slowly through the brownies. What if we took something with good thermal conductivity and kind of stuck it into the brownie? Aluminum is about 700 times better at conducting heat than brownie batter. At least according to the research I could find, it would act as a pipeline, bringing heat directly into the center of the brownie. Although a single rod would only work for stuff right around it. So, we would need a lot of rods to cook everything. It's kind of a weird bed of nails thing. It's going to be hard to make, but I think this should work. Let's find out. Can't see anything. Coolant makes it so hard to film. We got to fix this. The camera lens gets coated by chips and coolant. So, I made this. It's an air knife to blast off anything that gets on the lens. A sheet of air shoots out of here and it works really well. That is so much better. All right, now we can leave the machine to flail around for a couple hours and we got our pan. This turned out so cool. It's like the personal pan brownie. If you think about cooking brownies in this pan, they're going to be trapped in the spikes and you won't be able to scoop them out. So once the brownies are done, you unscrew the bottom and then slide the spikes out of the brownie. And the spikes are tapered, so I can hopefully get them out of the brownie without destroying it. And I wish I would have realized this problem at the beginning, but I didn't. I actually made a whole other pan. So now I have a cool paper weight, I guess. And then on the bottom of the spikes, it's something that just kind of happened. I saw that the stock I was using for the spikes had some extra material. I got a primal glint in my eye and machine the heat sink into the bottom. The thought is that maybe it'll help get some more heat into the spikes to cook the brownie. I don't know, maybe it'll just burn the bottom of the brownies, but it looks cool. I really want to put this in the oven and try it out, but it's hard to see through the window. So, I think we need a way to get a camera in the oven. And I'm imagining a sort of air cooled enclosure that will go around the camera and protect it, which should be very easy to make with this absolute unit of a 3D printer. It's a Form 4L. It's made by Formlabs. I actually used to work there making these machines and they called me up and said, "Do you have any use for one of these? " I said, "Uh, yeah. " So, here we are. One of the cool things about SLA printers is that they can print some very specialized materials like ceramics or dentures that go directly into your mouth or in this case withstanding high temperatures. And this material can handle up to about 500° F, which would turn normal 3D printed parts into a puddle. And I could have machined this, but it would be so much work and a lot of material. And I'm doing a lot of machining, so it's nice to just press a button and get some parts out. The camera sits on these ribs so that it's not directly touching the wall. You just put in like this, and the air gets pumped into this manifold, which distributes it to different points to make sure there's no hot spots. And this is the exhaust, which goes to another hose out of the oven. And this is really important. If we pumped a bunch of air into the oven, it wouldn't be able to hold temperature. Unfortunately, the tubes get crushed by the oven door. So, just don't tell my wife. I'm going to fix this when we're done. You won't even be able to tell. It's kind of like a camera spaceuit. I'm a little nervous about this pan. I really hope it works cuz I don't really have any other ideas. There's only one way to find out. This looks really good. The wife is back. Remember, she is a brownie expert. I think this looks like a real brownie. Also brownie pan. I already think it is more promising. She got the little crackly She loves that crackly top. Why are we putting it upside down? I'm going to unscrew the bottom. Interesting. First step, let's see if we can do this without destroying the brownie. I just want you to yank it off. Wow, it smells good. It just released some pherommones. If you blindfolded me and told me to cut that, I would say that's the center of a brownie for sure. What do you think? H, it's very close, but there is a little bit of an edge on the top. scale of 1 to 10, I was between a seven and an eight, so I'll say seven and a half. That was good. Definitely more brownie than cakes. So, why isn't a cake cooked like that? It's a good question. I thought about it and I it's like whatever. Now, I want a cake with edges. I suspect the mini edge could be fixed with cooking temperature and time. So, I made this little thing that can go on top of the pan to measure the temperature in the middle and on the edge. so we can see how things are

cooking and dial in our settings. Here's what I measured a normal brownie pan doing. And here's our spike pan. The temperature of the middle brownie closely tracks the edge and it also cooks quite a bit faster. All right, let's see if we can get rid of that little edge now. That is the opposite of what I wanted. This took longer than I was expecting. I've lost track of how many brownies I've made, but eventually I got it. And it turns out the brownies want to be cooked for less time at a lower temperature, which is kind of the opposite of what I expected. Look at this. It's perfect. think there's still an edge. There's not an edge. I think to get to the bottom of this, we're going to have to up our science a couple more notches. There's a thing that I've been thinking about which should very clearly answer the edge or no edge question. When you bite into a brownie, your teeth are cutting through it. And depending on how hard it is, you'll interpret it as an edge or a center. And what I want to make is sort of a mechanical mouth that will cut through the brownie and measure the force. And this will let me quantify exactly how hard or edgelike any brownie I make is. So, let's make it. I really like how this thing turned out. It's amazing how much better a little block of wood can make something look. And the way that it works is pretty simple. There's a motor embedded in this butcher block, which moves this little cart with a razor blade up and down. And the razor blade is pushed by this load cell, which measures how hard we have to push the blade. Now, we can measure exactly how hard the edge of any brownie is. And you probably didn't realize this, but it's actually against the law to make something like this and not stick everything you can possibly think of under it. Just kidding. This is a standard brownie edge. The force goes way up when the blade touches the brownie. Then it drops kind of in the middle. Then goes way up again when it hits a thick crust on the bottom. And then this is a nice soft brownie center. Once the blade hits the brownie, it's pretty much constant force all the way down. Pretty obvious difference. And it's so cool to see this thing actually measure it. And the only thing that matters is what the edge of my no edge brownie looks like. But for that, we need my wife. What is this contraption? This will tell us, is an edge actually different than the center of a brownie? And this is the latest and greatest from my pan. All right. How much money on your wallet? You going to make bets? I ain't even got no wallet. Give zel. Drum roll. Here comes the data. You ready? Looks the same. Does look the same. Corporate wants you to spot the difference between these two plots, which you can, I bet, cuz they're the same. Well, it's still not really a pan, though. But pan. Since when do you have to unscrew your pan to get your food out? It's also tiny. That's true. As is usually the case, my wife is right. Our whole goal was to make a real no edges pan and a little pan that you have to unscrew doesn't really count, especially because it doesn't scale. If I tried to make a full-size brownie pan like that, when I removed the spikes from the bottom, the brownies would just fall out. So, I was initially thinking to put the spikes on the top and you just remove them when the brownies were done. but it's just kind of weird. And you'd have to have a big air gap above the brownies for them to expand when they cook. And it'll also put pock marks all over the top of the brownies, which will just look bad. I want aesthetically pleasing brownies. So, I think the answer is retractable spikes. Essentially, a pan with a bunch of holes in the bottom that spikes will go through when it's cooking, and then the spikes get pulled down and out of the brownies when they're done, so you can cut and scoop them. Doing this in a user-friendly way is going to be more complex and less practical, but a lot cooler. My main fear is batter leaking out of the holes in the bottom of the pan. I've actually been mentally preparing to have to make a thing with hundreds of O-ring seals for every spike. I even made this tiny little micro pan to see if it could work. I really don't want to make this. So, I'm applying an advanced engineering technique called rationalization to convince myself that we don't need this. And we don't. The brownie batter is thick. The gaps are small. It's not going to flow through. It's going to be fine. Hopefully. It doesn't look like it yet, but this is a pan. This is one of those builds that uses every tool in the shop. This is the holy plate that all the spikes are going to go through. This is one of the walls of the pan. It's a great example of a part that five-axis makes so much easier. You'll see later, but they're covered in off-axis

features, and you can hit all of them in one setup. The rest of the five-axis parts are pretty similar to the other pan. All in, these pans made almost 50 gall of chips. And the whole thing is made in a weird way. I divided the upper and the lower pan into four pieces because it's a lot cheaper. And just ignore this. You didn't see this. Amazingly, all the parts fit together with just a tiny bit of filing. That's not normal. Finally, this thing is done. It was a lot harder to make than I was expecting, but it's also cooler than I was expecting. So, I think that's a good trade. And here's how it works. The handle locks down in this position when you're baking. When it's time to serve, you pull it out slightly and raise it up. And then you just push it down and it raises the roof. And the reason I have the handle pushed down instead of lifting up is that it takes a decent amount of force. And if you're lifting it up, you'd have to hold the pan down with your other hand, which is impossible to do with an oven mitt on. This is the pan that the brownies will bake in. And all the spikes come up through these holes. And then this is the lower section of the pan with the spikes. The important thing is this big flat surface. The upper pan rests tight against this, which seals the brownie batter in. This should work because the batter is thick. If we tried to fill the pan with water, it would leak. The brownie pan slides up and down on these guide rods, which have these weird grooves cut into them. These are for some special hardware called ball spring plungers. They're a screw with a spring-loaded ball in their tip. If you press hard on the ball, it can retract into the screw. There's four of these embedded inside the wall, which ride against these guides. So, when the pan is down, they snap into the groove and hold it tight. And up top, they snap into this groove to keep the pan from falling apart. Ball spring plungers are great, but don't get too excited cuz they're like $10 each. And then down in the bottom, there's a very overengineered looking mechanism, and it may in fact be, but I would argue that we actually need it. When this pan comes out of the oven, it's going to be flaming hot. Trying to slide the upper pan up without burning yourself would be a real challenge. But even if you waited for the pan to cool, there's another really big problem called racking. You've probably experienced it with a drawer getting jammed when you try to open it or maybe trying to slide a piece of metal on a rod. If the top pan tilts at all when you're trying to slide it, it will lock onto the rails. You really can't remove this by hand. It's just going to keep jamming the whole time. We need it to be slid up totally evenly, which is what led me to this ridiculous design. It pushes on all four corners of the pan simultaneously to lift it without racking. It's lever action. You can easily do it with an oven mitt on, which solves the burning problem. All the heavy lifting is done by these roller cams, which are joined together with linkages. They go over center when the pan's in the upper position, which locks it so you're not going to accidentally stab yourself on the spikes by pushing down. Isn't this thing awesome? It's maybe a little bit overkill. I mean, if I was working at Rubbermaid, I would design it differently, but I don't work at Rubbermaid, do I? This is stuff made. It's just a bigger version of the small pan, so it should work, but we won't know until we try it. So, here we go. Oh, man. That looks awesome. That is such a uniform brownie. All right, let me go get my wife before I just tear this thing apart and ruin it. Hey, wife. What? Is that not the most even brownie you ever saw? It is very flat. So, what do you think you need to do? I need to pull this. Obviously, this is the part that could be a little better. Pull the lever sideways and then back. Okay, there you go. And then I still pull it back. Push it forward now. Wo. Okay, but now it's just floating. How do I get this out? No, just leave it. It's just ready to serve. How do I cut it and get it out like any other normal brownie? All right, let's see. Get you a bite of that edge. It's a nice little chum. Would you have ever known that was an edge? I would have wondered what happened to the bottom of it. Scale of 1 to 10. I mean, I think it's a 10. Has no edge. It would be walked all over if it was a person. I spent way too long trying to get a nice clean cut. Other than the cut being a little rough, the outside looks just like the inside. If you were at a party and you have a tray of brownies and you want the middle, you're going for this piece. Should do an infomercial. That's a good idea. I've been cooking brownies over and over, and waiting for them to finish gave me a lot of time to kill. So, I started messing around with stuff in my

shop. You know how it goes. One thing leads to another and the next thing you know you've built a mortar. It's pretty cool. Dropping a bearing and then [clears throat] and I was wondering can I shoot a ball into this cup from a distance which is the kind of thing you do when you're waiting for brownies to finish. But the problem is I don't know how to aim it. To figure this out I shot bearings at a few different angles and wrote down where they went. Then I fit a polomial to that data which I can use to calculate exactly where I need to point this. So, the ball will go wherever I want. Being able to whip out calculations like this honestly feels like a superpower. And I'm not trying to brag. I wish everyone could do this, which is why I'm a huge fan of this video sponsor, Brilliant. You can think of Brilliant as a tool that's fine-tuned to teach you technical stuff, things like math, programming, data science, AI, all kinds of useful stuff. But what really sets Brilliant apart is that all the lessons are interactive. They teach you the theory, but you spend most of your time applying it to solve actual problems. Which is why I just love projects like this one. The best way to learn something is to actually do it. Another challenge when you're trying to learn something new and complex like AI is where to even begin. Brilliant solves this by breaking topics down into a series of bite-sized lessons. They build on top of each other and they're just the right size to do one or two a day, which makes it easy to develop a daily learning habit, which I cannot stress how useful this is. I set aside 30 minutes every day to learn something new. And what's been really surprising about this habit is how easy it is. It doesn't feel like you're doing that much dayto-day, but fast forward a month and suddenly you're nailing ball bearing trick shots with linear algebra. So, if you're ready to level up your technical skills or maybe just relearn stuff that you forgot, check out Brilliant. You can try it for free for 30 days. Just go to brilliant. org/stuffade here. You can also click the link in the description or scan the QR code. And if you like it, you'll also get 20% off an annual premium subscription. Now, it's the moment of truth. 59. 2° should go in that cup. Here we go. Three, two, one. Yes, that totally went in. Didn't stay in, but that went in the cup. Knowledge really is a superpower. So, I hope you check out Brilliant. And thank you, Brilliant, for sponsoring this video. Tired of brownies that are gooey in the middle and burnt on the edges? Introducing the Iron Maiden Pan. The only pan that bakes from the inside out. It's 272 painstakingly crafted metal spikes make every bite torturously perfect. Your brownies will scream with flavor. Handmade in the most expensive way possible. It could be yours for one easy payment of $899. 99. Call now. Operators are standing by. Probably