Cookies are pretty well the most useless item in the game. It's not bad to have the occasional useless item, but when cookies were introduced, they had a use. They were the only stackable food item. Now, every food item is stackable. They don't heal as much as anything else, except watermellons, and watermellons have their own use, being the most easily mass-produced food. Cookies are exceedingly rare, and absolutely useless.
Something I'd like to see is cocoa beans have a chance to drop from jungle tree leaves. This does make cookies renewable, but not exactly common. I'd like to propose that cookies give an eight-second speed boost. That makes cookies a rather useful food, particularly in combat. Cookies are to speed potions what golden apples are to regeneration potions. A less powerful, but more practical, alternative.