A patty pan is a baking tray with small, shallow round holes. This type of tray is popular for use when making tarts, small cakes, quiches and butterfly cakes. If you don't have a patty pan tin, you can use an old fashioned gem iron pan. Alternatively, you can bake the mixture in a regular muffin tin and then cut each of the sponge cakes in half once cooled to make smaller cakes.