Flo Braker’s all-American chocolate cake is basically my favorite chocolate layer cake and there is no cocoa in it. It’s different from the devil’s food recipe.
There is an error in Baking for All Occasions regarding the chocolate, so I always link to this blog whenever I rave about it:
https://scratch.typepad.com/scratch/2009/03/dark-chocolate-cake---flo-braker.html
I’ve never made cupcakes with it, so I can’t say anything about timing.
For a more typical chocolate cake (the standard runny batter, oil-based kind most American chocolate cakes are like) this one is great and has cupcake directions.
So is Stella Parks’ devil’s food cake.
Alice Medrich also has really good chocolate cupcakes, both made with unsweetened chocolate or with cocoa powder.