Recipe: Chocolate Cupcakes with Sour Cream Fudge Frosting (Williams-Sonoma recipe)

CHOCOLATE CUPCAKES WITH SOUR CREAM FUDGE FROSTING

1 cup all-purpose plain flour
1 cup plus 2 tbsp. white granulated sugar
1/2 tsp. baking soda
1/4 tsp. salt
3/4 cup milk
1/2 cup unsalted butter
1/3 cup firmly packed unsweetened cocoa powder
1 large egg, at room temperature
1 tsp. vanilla extract
Sour Cream Fudge Frosting (recipe follows)

Position a rack in the middle of an oven and preheat to 350 degrees F. Line 10 (1/2-cup) muffin pan cups with paper liners.

Sift the flour into a large bowl. Stir in the sugar, baking soda and salt; set aside.

In a heavy saucepan over medium-high heat, combine the milk, butter and cocoa powder. Bring to a boil, whisking constantly.

Remove from heat and add to the flour mixture, whisking until well combined. Whisk in the egg and vanilla extract until blended. Spoon an equal amount of the batter into each prepared muffin cup.

Bake until a toothpick inserted into the center of a cupcake comes out clean, about 20 to 25 minutes. The cakes will be flat on top when they are baked. Remove from the oven and immediately invert onto a rack. Turn the cupcakes right-side-up. Let cool completely.

Spread about 2 tablespoons of frosting over each cooled cupcake. Store in a single layer in an airtight container and refrigerate up to two days.

SOUR CREAM FUDGE FROSTING
Makes about 2 2/3 cups

"This is a luscious, silky-textured frosting."

3/4 cup unsalted butter
3/4 cup heavy (whipping) cream
10 ozs. bittersweet chocolate, chopped
3/4 cup sour cream
1 cup confectioners' sugar

In a medium-sized, heavy saucepan over low heat, combine the butter and cream. Heat, stirring frequently, until the butter melts. Add the chocolate and whisk until melted and smooth, about 2 minutes. Remove from heat and let cool to barely lukewarm, about 8 minutes.

Whisk in the sour cream until fully combined. Then whisk in the Confectioners' sugar. Let stand until thick enough to spread, about 10 minutes. If the frosting become too stiff to spread, rewarm briefly over low heat and whisk again until smooth.

VARIATIONS:
For a sweet variation, sprinkle with crushed peppermint candies before serving.

For mocha flavor, add 1 tablespoon instant espresso powder or regular coffee powder to the butter and cream while making the frosting.

Makes 10 cupcakes
Adapted from source: Williams-Sonoma Kitchen Library: Cakes, Cupcakes and Cheesecakes by Sarah Tenaglia and Chuck Williams