I made these cupcakes for my dear roommate's 23rd birthday!
For the cupcakes:
1 package chocolate cake mix with pudding (I used Pillsbury)
1 c. sour cream
3/4 c. water
1/2 c. vegetable oil
3 large eggs
1 tsp. pure vanilla extract
For the filling:
4 oz. frozen whipped topping, thawed
1/2 c. (4 oz.) sour cream
1/2 c. confectioners' sugar
1/2 tsp. vanilla extract
For the frosting:
1 1/2 sticks butter
1/2 c. unsweetened cocoa powder
1/2 c. milk
5 1/2 c. confectioners' sugar
Preheat oven to 350 degrees. Line 24 cupcake cups with paper liners.
Place cake mix, sour cream, water, oil, eggs, and vanilla in a large mixing bowl and beat with an electric mixer for about 2 minutes, scraping down the sides halfway through. Scoop batter into cupcake liners, filling them about two-thirds of the way full. Bake 16-20 minutes. All cupcakes to cool for 20 minutes before filling.
Make the filling: Use an electric mixer to combine whipped topping, sour cream, confectioners' sugar, and vanilla in a bowl until all ingredients are well incorporated.
Spoon the filling into an icing bag with a Wilton 230 tip and squeeze about 2 tablespoons of the filling into each cupcake. Chill cupcakes in refrigerator while you make the frosting.
Make the frosting:
Melt the butter in a medium-size saucepan over low heat, 2-3 minutes. Stir in cocoa powder and milk. Cook, stirring, until the mixture thickens and comes to a boil. Boil for 1 minute, remove from heat, and stir in confectioners' sugar. Spoon a generous amount of frosting onto the cupcakes.
[recipe from The Cake Mix Doctor Returns by Anne Bryn].