Preheat oven to 375 and spray 10-12 muffin tins with cooking spray.
mix together the egg and melted butter and cake mix.
Place 2 tablespoons of dough into each muffin tin and flatten it inside the tin until it is abou 1/4 inch thick all around. Bake for 12-15 minutes, or until cups are done. If the cups get kind of puffy, smoosh them with a spoon so they are flat.
Cool the cups in the pans for 10 minutes and then remove thenm to a tray or rack. Be sure they are cool or they will fall apart.
Fill them with ice cream or pudding whatever you like.