I suppose we could debate whether these are really brownies or cupcakes, but why waste time when we could be eating them. They're chocolate brownie cupcakes with peanut butter frosting, and yes, they're as amazing as they sound.
You can experiment with various brownie and frosting recipes to get the combination you like best. My favorite so far though is this one from Epicurious. I love the addition of the toasted walnuts in the brownies, and this frosting, with the optional whipping cream, is light, fluffy, and fantastic.
Chocolate Brownie Cupcakes With Peanut Butter Frosting
6 tablespoons (3/4 stick) unsalted butter, cut into 4 pieces
1 1/4 cups semisweet chocolate chips (about 8 ounces)
3 ounces unsweetened chocolate, chopped
1/2 cup (packed) golden brown sugar
1/3 cup sugar
2 large eggs
1 teaspoon vanilla extract
1/2 cup all purpose flour
1/3 cup walnuts, toasted, chopped
1/4 teaspoon salt
1 cup powdered sugar
3/4 cup creamy peanut butter (do not use old-fashioned or freshly ground)
1/4 cup (1/2 stick) unsalted butter, room temperature
1/4 teaspoon vanilla extract
4 teaspoons (about) whipping cream (optional)
Chocolate shavings or chocolate sprinkles for topping (chopped up peanut butter cups are amazing on top too!)
Preheat oven to 350°F. Line 10 standard (1/3-cup) muffin cups with paper liners.
Combine butter, 1/2 cup chocolate chips, and unsweetened chocolate in top of double boiler set over simmering water. Stir until mixture is melted and smooth.
Remove from over water. Whisk both sugars into chocolate mixture, then whisk in eggs 1 at a time. Whisk in vanilla, then flour, walnuts, salt, and remaining 3/4 cup chocolate chips.
Divide batter among prepared muffin cups (about 1/4 cup for each). Bake cupcakes until tester inserted into center comes out with moist crumbs attached, about 20 minutes. Transfer cupcakes to rack and cool completely.
Put powdered sugar and next 3 ingredients in medium bowl. Using electric mixer, beat until mixture is smooth, adding whipping cream by teaspoonfuls if frosting is too thick to spread.
Spread frosting in swirls over top of cupcakes. Sprinkle with chocolate shavings or chocolate sprinkles.
Image via Shrie Bradford Spangler/Flickr