In AZ (at least in the city of Tucson) any item that is a prepared food is required to collect tax. When I called the division, they said that food from the grocery store did not collect tax, and the test was if the store where you purchased it took food stamps as payment
If it did, then you didn't have to pay tax. Which boggled my brain on that a plastic domed birthday cake from Safeway was not taxed, but a counter service bakery would have to charge tax? Huh? Regardless of that, she said that specialty food providers are considered to be like a caterer, and that requires tax.