Perhaps the most adorable cake in the whole Heavenly Cakes book--Miette's Tomboy is the signature cake of its eponymous bakery. It's also really really really good. It's an oil cake, made mostly with cocoa but also with one ounce of chocolate dissolved in boiling water. The cocoa I used was a very special dark cocoa that I got at Sahadi's--it's so black that it looks blue in the mixing bowl, and it makes a very very dark cake.
I actually made this cake for the first time a few weeks ago, when the rest of the group did, but I never got around to frosting it before we ate it. Since it was little (6 inches), I figured there was room to try again. Also, the first time I didn't really properly beat the egg (one egg doesn't beat so well in the large bowl of my old mixer, so this time I tried the smaller bowl), and so the cake sank dramatically in the middle. This time it had much more height, though there was still a dip. The mixer also can cause problems for making mousseline buttercream, as I often have problems getting the sugar syrup in without it crusting on the sides of the bowl. This time was a win, possibly the best and fluffiest mousseline I've ever made (tilting the bowl to get a better temperature read on the sugar was also wise). Matt had a slice (after a very dedicated photo session--he said it was fun to shoot) and said that it tasted very similar to an Oreo cookie. I haven't tried it yet, but based on various scrap samples, I'd agree. The piping--well, I got carried away by the leftovers and so the top wasn't flat. But it's pretty cute, no?