I'm actually going to suggest yellow cake with vanilla icing, as I think the chocolate would cancel out the flavor. Of the cake.
yellow cake with chocolate icing!! the best cake/icing combination there is. i actually just made one last week. mmm... plus eating the left over yellow cake batter is my favorite part!
haha. I didnt make the icing. It was store bought betty crocker icing. i think it was the milk chocolate rich and creamy kind. If you buy the icing, and whatever brand you buy, i recommend not buying the "whipped" icing.