Pop-Tarts is a brand of rectangular, pre-baked toaster pastries

Toaster pastry

A toaster pastry is a type of pastry, designed to be safely heated in a toaster. It is a convenience food, generally intended to be eaten for breakfast, but is often a snack...

 made by the Kellogg Company

Kellogg Company

Kellogg Company , is a producer of cereal and convenience foods, including cookies, crackers, toaster pastries, cereal bars, fruit-flavored snacks, frozen waffles, and vegetarian foods...

. Pop-Tarts have a sugary filling sealed inside two layers of rectangular, thin pastry crust. Some varieties are frosted

Royal icing

Royal icing is a hard white icing, made from softly beaten egg whites, icing sugar , and sometimes lemon or lime juice. It is used on Christmas cakes, wedding cakes, gingerbread houses and many other cakes and biscuits, either as a smooth covering like marzipan, or in sharp peaks...

. Although sold pre-cooked, they are designed to be warmed inside a toaster

Toaster

The toaster is typically a small electric kitchen appliance designed to toast multiple types of bread products. A typical modern two-slice toaster draws anywhere between 600 and 1200 W and makes toast in 1 to 3 minutes...

 or microwave oven

Microwave oven

A microwave oven is a kitchen appliance that heats food by dielectric heating, using microwave radiation to heat polarized molecules within the food...

. They are usually sold in pairs inside foil packages, and do not require refrigeration.

Pop-Tarts are Kellogg's most popular brand to date in the United States, with millions of Pop-Tarts sold each year.