I made a 3-layer devils' food chocolate cake (each layer was 6x6x2in). It was supposed to have a delicious, homemade buttercream frosting, but I managed to create butter-egg-sugar soup instead. Not sure what I did wrong there. Instead, I just used store-bought buttercream (not nearly as good) because I was almost out of time.
I also had my first experience with fondant -- which went better than I expected -- in creating the decorations.
As promised, you can find a picture of the cake here.