* I didn't have cocoa powder so for the cake batter I just used one square of bakers chocolate - you melt it anyway so it worked just fine! For the frosting, I just chopped up some semi-sweet chocolate chips and added them instead of the pecans.
* "Frost immediately" might not exactly be recommended. I was skeptical about putting a buttercream frosting on a pretty warm cake. And I was totally right to be - a lot of it melted right off the edge. I threw it in the fridge right away though so I was able to save most of it!