Well let's see what they're both like.

Cake- big, can be round or any shape, more frosting,can have secrets inside.

Cupcakes-small, round, little frosting,can have secrets inside.

Well it depends on the type of cake they are but I don't like to much frosting if it tastes weird or ever I guess...  But I find it interesting when the icing/frosting stains your face...