Same thing here, I followed this recipe : http://presleyspantry.com/2013/01/07/oreo-nutella-brownie-cupcakes/....and it turns out to be.......really really.....WOAH!
1/4 stick of butter (unsalted)
1 cup of sugar (caster)
Mixed it
Add 3 eggs & 1 1/2 teaspoon of vanilla extract
Add in the flour
In this case, I added the *almost-whole-jar* of Nutella
MIX MIX MIX
Put 1 tablespoon of the batter into e mould. Oreo. Then another 1 tablespoon of batter.
Put it in a preheated 180 degrees oven, bake it for 20 mins or so....
Top it with chocolate frosting (shld try out the Nutella frosting)
Little Devil's cupcake............Sinful yet irresistible.