A layer cake (US English) or sandwich cake (UK English), also called a sandwich in UK English, is a cake consisting of multiple stacked sheets of cake, held together by frosting or another type of filling, such as jam or other preserves. Most cake recipes can be made into layer cakes; butter cakes and sponge cakes are common choices. Frequently, the cake is covered with icing, but sometimes, the sides are left undecorated, so that the filling and the number of layers are visible.