Before your embark on this experimental cooking endeavor, please ensure that you have the following items:Ingredients:Pizza Dough -- Although any type will do, I used the kind that comes in a tube. This required 5 tubes, or around 3 lbs.Pizza Sauce -- Depending on your preference, between 16 and 32 oz.Cheese -- Mozzarella, shredded. About 2 lbs.Toppings -- I kept it pretty simple, and just used pepperoni for this attempt; roughly 12 oz. However, as this is an experimental pizza, embellishment is certainly encouraged. (For those of you keeping track, this is over seven pounds of ingredients. The formula for calculating the volume of a sphere, (4/3)pi*R^3, means that a sphere can hold a lot more pizza than a circle.)Equipment:2 Hemispherical Bowls -- I used stainless steel bowls with a 9" inner diameter.Rolling Pin -- or some similar device for rolling out your dough.Oven Mitts -- two of them, for removing the bowls from the oven and combining them. (potholders not recommended)Optional: Flour -- to keep the dough from sticking to your counter top. Non-stick cooking spray -- to keep the dough from sticking to the bowls. Needless to say, you'll also need an oven in which to cook this. Also, a reasonable amount of clear counter space for rolling out the dough.

Start by coating the inside of your bowls with a non-stick substance such as Pam or Crisco. Now spread a small amount of flour over the area of the counter top you'll be working on. Next, take the first tube (bag, bucket, etc.) of pizza dough, and roll it out on the counter where you put the flour. Don't roll it too thin, as this will be the "structural" crust, which will (theoretically) support the weight of the sphere. If you're making this pizza sphere in the presence of gravity*, there will inevitably be some degree of collapse of the shape, but a reasonably thick crust, properly cooked, should minimize this to some extent. Line the bowl with the dough. It may help to wipe the non-stick spray off the very top edge of the bowl, and then press the edges of the dough onto the edge of the bowl. Otherwise the dough will have a tendency to slide down into the bowl. Now put a layer of cheese and toppings in the bottom of the bowl, and you're ready to start making the center. *If you're making this in zero/micro gravity, please send me pictures!

Take the next quantity of dough and roll it out to about 1/4" thick. You want to make it as large as possible without making it so thin that it will tear apart when you try to move it. Now cover the dough with your sauce, toppings and cheese. I used two layers (with double cheese) to make it thicker (sauce, cheese, pepperoni, cheese, sauce, cheese, pepperoni, cheese) but even three layers would not be unreasonable. The idea is to make enough volume of pizza to fill the bowl. You should now have something that resembles the first image. At this point, carefully roll the corners towards the center. It should look like the center picture. Now roll the new corners inward. This is to ensure that the center is made of layers of cheese/toppings and dough, rather than having one big glob of cheese and toppings in the center. Next, take your rolled up pizza ball and put it in the bowl. Cover this with another later of sauce, cheese, and toppings. Once you've done this, repeat this step and the previous one with the second bowl. But first, this is an excellent time to start pre-heating your oven.

This is where things get a bit tricky. As I mentioned earlier, this is my second attempt at making a spherical pizza. The challenge with cooking a solid mass of dough and pizza toppings is finding the right time and temperature combination to cook it all the way through without burning the outer crust. (It's been suggested that I try cooking this in a microwave, as those cook "from the inside out". This is a myth. Microwaves will not penetrate all the way to the center of a mass of dough this size. Also, the only proper sized bowls I had were stainless steel, which does not play well with microwave ovens.) By this point, you should have two bowls of pizza ready for the oven. I cooked mine for about 2 hours at 325 degrees. I think if I try this again, I would try 275 degrees for 2 and a half hours. The outer crust was quite crispy (but not burned), and the center was just a bit undercooked. I cooked the two halves side by side for one hour, then added a center piece (which I'll discuss more in the next step) which was intended to hold the two halves together. I then cooked the whole thing (the two halves put together) for another hour. Cooking the two halves separately for the entire duration, with no center piece, I think about 1.5 hours at 300 degrees, or two hours at 275 degrees would probably be just about right. That should also provide plenty of time for cleaning up the mess you've made up to this point.

The following is an extra step I performed, which I do not recommend, but will describe for informational purposes so that that you can improve upon what I did. While the two halves were baking, I used the final tube of dough to make a center piece. I rolled out the dough, covered half of it with cheese and toppings, then folded it in half and put it between the two halves, with cheese on the top and bottom. The idea was that this would bake and solidify in between the two halves and hold the two together. The problem with this theory is that the center is added when the two halves are combined, and in this case, the two halves were already mostly cooked by then. This means you have less time for the center to cook through before the outer crust burns, resulting in an undercooked inside.  The obvious solution is to put this on and combine the halves before cooking them. However, cooking the whole thing combined with make it almost impossible to cook all the way through without burning the crust--there's less area exposed to the hot air, again resulting in an undercooked inside. I ended up having to cut out the center and cook it for half an hour on its own, so I would recommend simply skipping this step.

Assuming you omitted the previous step, you should now have two fully cooked half spheres of pizza. Using a pair of oven mitts (I don't recommend using potholders for this--you're much more likely to accidentally burn yourself), remove the halves from the oven and flip one half over on top of the other. (you may choose to let them cool for a bit before combining them) Let your Pizza Sphere cool for about 15 minutes before removing from the bowl. This will let the cheese solidify a bit and hopefully reduce the amount that the sphere collapses under its own weight. Once it is sufficiently cooled, place one hand on top (still using the oven mitts--that bottom bowl will probably still be pretty hot) of the sphere, and flip it over onto a large plate/platter or cookie sheet. (or a flat pizza pan if you're feeling ironic) Remove the bowl and marvel at the three-dimensional ball of pizza you've created!! I recommend cutting your Pizza Sphere in half to allow it to cool faster. The outer crust can be broken apart and eaten like regular pizza; the inside may require a knife and fork.