Pop-Tarts is an American brand of toaster pastries produced and distributed by Kellanova since 1964. The pastry consists of a sweet filling sealed inside two layers of thin, rectangular pastry crust. Most varieties are also frosted. Although sold precooked, they are designed to be warmed inside a toaster or microwave oven. They are usually sold in pairs inside Mylar packages and do not require refrigeration. They are marketed primarily as a breakfast food, but can be eaten as a sweet snack food.