A pancake is a flat cake, often thin, and round, prepared from a starch-based batter that may also contain eggs, milk and butter and cooked on a hot surface such as a griddle or frying pan, often with oil or butter. In Britain, pancakes are often unleavened, and resemble a crêpe. In North America, a raising agent is used (typically baking powder). The American pancake is similar to a Scotch pancake or drop scone. Commercially prepared pancake mixes are produced in some countries.