Yeah, the same rocket scientists who decided that a Twix bar is food, but a Snickers bar is not are now grappling with the definition of store pizza.  Here’s an article from The Pew Charitable Trusts:

Call it the great “take ‘n’ bake” pizza sales tax dilemma.

States are grappling with whether sales taxes should be charged for pizzas or other food assembled uncooked in restaurants and sold to consumers who then cook the food elsewhere.

Is that pizza considered prepared food, like that sold by pizza restaurants? Or is it a grocery item, like the frozen pizzas in supermarkets? In most states, food that’s sold ready-to-eat is taxed; food sold in the grocery store and cooked at home is not.

That sounds as complicated as the “candy” definition states had to settle. After grappling with that one for years, the Streamlined Sales Tax Governing Board, which attempts to regularize sales taxes among states, decided that candy is defined as something without flour in it, and candy-like items made with flour as an ingredient are defined as “food.”  Most states tax candy or snacks, but not food. So, a Twix bar is food and a Hershey bar is not, at least according to the official tax definition.  Read more here: