Here is how I made a chocolate drum cake for the wife of a coworker. This actually looks like her real favourite drum.
Step 1: Cake
Make chocolate cakes. Big ones! Put them on a cake board and cover them in buttercream icing. Let the buttercream set in the fridge for 30 minutes.
Don't have cake boards? Neither did I. Cut a circle from a pizza box and cover it in tinfoil.