I think this tutorial (Mini Cakes DIY) is the one I'm going to try, it's from Ohhappyday.com. Depending on how much frosting (I mean, how much is too much? I love frosting) I make, I'll probably frost all the way around and maybe only make them two layers...
And here's the other resource I found, same idea really. How to Bake Mini Cakes
Other options... using cupcake/muffin pans!
Caitlin, from the wedding chicks blog, created these with photo step-by-step instructions. Which was really nice of her.
I don't know the original source for these so I'll just link to where I found it. How to make mini cakes from cupcakes