by bill herian » Sat Apr 13, 2013 2:56 pm
...Basic geometry tells us that the perfect cookie would be a sphere, this is made impractical by conventional ovens and the fact that we cannot ensure evenness of baking, so we have to find a happy medium. This is why cookies are way better when made into bars on a baking sheet. You imporve the surface area per volume ratio and the entire product is cooked a uniform and sastisfactory level of doneness. This is also useful when baking for groups. Instead of wondering how many cookies your dough will produce, or how large to make them in order to get a certian number, slap that shit in a pan. That's how many bars you got.
This was taken from:
Bill's Big Book of Modern Cookiecraft. 2nd Edition: Contemporary Cookie Theory Revisited