I don't know where this recipe came from, but anything with peanut butter and chocolate is a winner in my book. The recipe only makes 12 cupcakes, so you might want to double it.
1 cup flour
1 1/2 teaspoons baking powder
pinch of salt
1/2 cup dark brown sugar
1/4 cup chunky peanut butter
3 tablespoons unsalted butter
1 large egg
1/2 cup milk
1/2 cup chocolate chips
In a bowl whisk together flour, baking powder and a pinch of salt. In another bowl cream together brown sugar, peanut butter and butter. Add egg and beat well. Add flour mixture alternately with milk, beating well after each addition. Stir in 1/2 cup chocolate chips. Spoon into cupcake pans. Bake at 350 degrees for 20 to 25 minutes.
Frosting:
Melt 3/4 cup chocolate chips over warm water (I just microwaved them for 30 seconds). Beat in 1/4 cup heavy cream and whisk until cool and fluffy.
Note: This frosting is semi-sweet. If you want a sweeter frosting use milk chocolate chips, or try the chocolate frosting recipe from the February 13, 2011 post (Chocolate Cake).