This was another really easy, but very effective cake I made recently. I took it to a friends house for Easter lunch and it went down very well - I was actually really shocked how simple and quick it was.
Starting off with 2 chocolate sponges (any recipe, or if you really aren't into baking you could buy them) I simply sandwiched them together with chocolate buttercream (you can also buy this ready made) - no need to be neat and tidy, you won't see it once its decorated, then I placed Cadburys Chocolate Fingers round the side (you could use kitkats) and covered the top with Maltesers.
And thats it! Everyone who saw it thought it looked great and didn't believe me when I said how easy it was.