Chocolate + Peanut Butter + Cupcakes = Yes. At first I thought it was chocolate chip cookie dough on the very top-- which makes me think that could be tried, too. Chocolate batter, gob of peanut butter in the middle, cookie dough on top.
Reese's Peanut Butter Bars - 5 minutes from bowl to pan, no baking. Took me more like 20 minutes but delicious. Very sweet so could serve a lot of people. Not quite a reeses peanut butter cup but just as good.