Yes! There will be leftover cake as you're cutting out hearts from a rectangle cake. Firstly, you can make more than three layered cakes, or make some one layer cakes. Or you can make cake balls (which I what I did!) - mix the leftover cake with the leftover buttercream in a large bowl (you just need enough buttercream to make the cake stick together). Roll into small truffle sized balls, then you can freeze for up to 6 weeks. Then when you want to eat them, defrost at room temperature and dip in melted chocolate for a quick cake pop!