A sheet cake or slab cake is a cake baked in a large, flat, rectangular cake pan. Sheet cakes are usually 2 inches deep, although they are sometimes 3 inches deep. These single-layer cakes are frequently frosted, with decorations and ornamental frosting along the borders and the flat top surface.
Sheet cakes may be made in any flavor, with chocolate and vanilla being the two most common. Commonly made in the home with boxed cake mixes, they can come in a variety of additional flavors, with batter mix-ins such as sprinkles and chocolate chips. By definition, they are made from a single continuous piece of cake. Ingredients such as nuts, chocolate chips, or coconut may be sprinkled over the top.
A layer cake may be made from a sheet cake that has been split, filled with jam or icing, and frosted.