Leftover cake
rum or rum aroma
jam/jelly of choice (just avoid chunks. I used apricot jam.)
chocolate (I used some dark chocolate but you can use whatever you have on hand. If you don't have any, just leave it out. The sprinkles stick better to the ball when you cover it very thinly with chocolate and you will have to miss out on that very satisfying 'crack' when you dig in with a fork, but there will hardly be any change in flavour)
chocolate sprinkles
dutch process cocoa (optional. If your leftovers don't have any cocoa but you want some, there you go)
cupcake baking liners (optional)