Cakes need layers. You can bake a boxed cake in a jelly roll/cookie pan lined with parchment. That easily makes 4 layers.
My frosting consists of one block of cream cheese mixed with a jar of vanilla curd. I guess I didn't really make anything in this cake. Mixing random stuff together still makes a pretty good cake.
Adding fruit to a cake makes it healthy. You can substitute a cake with fruit for any meal. My children agree.