The Ontology of Cupcakes

So, if you have a piece of cake and a cupcake of the same volume and from the same batter, are they equivalent? Is a cupcake and a piece of cake variants of the same thing or are they different types of things? In solid state physics, you see how surfaces have different properties from the insides of materials, is a cupcake a different thing because of the increased external surface area compared to pieces of cake? Is the difference in the application of icing meaningful? If you were given a choice between a piece of cake and an equivalent sized cupcake, would you have a preference? If so, does this indicate a difference or is it purely a matter of pragmatic elements -- that one is more easily portable?