It has occurred to me that it is not possible to bake a dozen brownies. The thing which comes out of the oven is not brownies. It is a proto-brownie mass which must be cut into twelve pieces to yield a dozen brownies. The act of cutting is as essential to making brownies as the act of baking.

I can think of no other baked item which shares this characteristic. Cookies and cupcakes are baked individually. Cakes and pies are cut, but each serving is a piece of the whole. A brownie is not a piece, it is the whole, but it is defined by the act of cutting.