Boston Cream Pie Cupcakes

Cake
1 1/4 cups all purpose flour
2 teaspoons baking powder
1 1/2 teaspoons meringue powder (optional, but recommended)
1/4 teaspoon salt
6 tablespoons unsalted butter, softened
2/3 cup granulated sugar
2 large eggs, room temperature
1 teaspoon vanilla extract
1/2 cup buttermilk
1/4 cup sour cream

Filling
1 large egg yolk
1/2 cup heavy cream
1/4 cup granulated sugar
1 1/2 tablespoons cornstarch
1/8 teaspoon salt
1 tablespoon unsalted butter
1/2 teaspoon vanilla extract

Ganache
1/2 cup semisweet chocolate chips
3 tablespoons heavy cream

Heat oven to 350 degrees F. Coat a (12 cup) muffin pan with cooking spray or line with paper liners.

To make the cake, in a medium mixing bowl, sift together flour, baking powder, meringue powder and salt. In a large bowl, using a mixer on medium speed, beat together butter and sugar until creamy - about 2-3 minutes. Beat in eggs and vanilla until well combined - about 2 minutes. Beat in buttermilk and sour cream until combined -about 1 minute. Reduce mixer speed to low and gradually beat in flour mixture until just combined. Divide batter into muffin cups; bake 15 minutes or until cupcakes are well risen and cake springs back when touched. Cool on wire racks.

To make the filling, whisk egg yolk in a small bowl. In a small saucepan over medium heat, whisk together cream, sugar, cornstarch and salt until well combined; continue to cook, whisking frequently, until mixture is hot. Gradually pour half of the hot cream into egg yolk, whisking constantly. Whisk egg yolk mixture back into saucepan with remaining cream. Cook mixture for 1-2 minutes, whisking constantly, until thickened and coats the back of a spoon. Strain custard into a small bowl and stir in butter and vanilla until combined. Chill custard over an ice bath, in refrigerator, until it reaches room temperature.

To make the ganache, in a medium bowl, stir together chocolate and cream. Melt mixture in the microwave for 1 minute, stirring every 20 seconds, until melted and smooth.

To assemble cupcakes, scoop out a tiny bit of cake from the center of each cupcake and place a spoonful of custard into the center. Spoon and spread chocolate ganache on top of cupcakes.

Makes 1 dozen cupcakes
http://www.visionsofsugarplum.com/2010/10/boston-cream-pie-cupcakes.html