Build Cooking

What does the cooking do? For most of the game, it only eats/wastes your boosts for no benefit, so it takes longer for you to get the other specials :) It is literally just a stat that 4G added to get in the way of leveling up an item for its more useful bonuses.
In other words, if you have a Level 0 Chef's Apron, you need to add 30 Special Boosts to it before you can start leveling the Energy Power boost. (So you could also say, it requires 30 + 50 Special Boosts to level the Chef's Apron to the max.)
Much later in the game, the Cooking ability can be unlocked, and take advantage of these bonuses. Note that (as of Build 1.260), each item affects "Total Cooking Bonus" equally, despite drastic differences in displayed "Cooking %" values.
Currently there are only 2 accessories with Cooking.