Chocolate Birthday Cake with Milk Chocolate Frosting

For the cake:

• 4 oz. bittersweet chocolate

• 2 cups all purpose flour,

• 2 teaspoons baking soda

• 1 tsp. salt

• ¾ cups sour cream

• 1 cup warm water

• 1 ⅓ cup light brown sugar

• 4 oz (1/2 cup) unsalted room temperature butter

• 3 eggs

• 1 Tbs vanilla extract

• 1 tsp instant espresso mixed with 1 Tbs. of water

For the frosting:

• ⅔ cup whole milk

• 8 oz milk chocolate and 2 oz. bittersweet chocolate

• 3 egg yolks

• 1 tablespoon flour

• 1 1/3 cup confectioners sugar, divided

• pinch of salt

• 1 tablespoon vanilla

• 1 cup (8oz) unsalted butter at room temperature

Preheat oven to 325°F. Line a 9 x 13 cake pan with parchment paper and spray with non-stick spray. 

Melt chocolate. Set aside and let it cool slightly. 

In a medium sized bowl combine flour, baking soda, and salt. Set aside. 

In another medium sized bowl combine sour cream and water. Set aside.

In a large bowl cream together brown sugar and butter until light and fluffy, about 3 to 4 minutes. Add eggs, vanilla extract and the instant espresso mixed with water. Mix well. Add melted chocolate and mix until completely combined. 

Alternate adding in the flour and sour cream mixture, starting and ending with the flour mixture.  

Divide batter among prepared cake pans. Bake for 35 - 40 minutes or until a toothpick comes out clean. Let cakes cool slightly in the pan, then remove from pan and let cool completely on a rack. Wrap with plastic wrap and refrigerate overnight (or at least until cold - you could throw it in the freezer for a few minutes if you are in a hurry).

To make the frosting, Heat milk in a small pot over moderate heat until hot.  

Melt milk chocolate and bittersweet chocolate. Set aside and let cool slightly. 

In a separate bowl whisk together egg yolks, flour, 1/3 cup confectioners sugar, and a pinch of salt in a bowl. Whisking constantly, add the add hot milk in a stream. Transfer mixture  to saucepan and bring to a boil over moderate heat, whisking. Reduce heat and simmer, whisking, for about 2 minutes or until the mixture becomes very thick. Transfer to a large bowl and cover surface with plastic wrap and let cool completely, about 45 minutes.

Add vanilla and remaining powdered sugar  to the cooled custard mixture beat on medium until well combined. Increase the speed to medium-high and beat in butter, 2 tablespoons at a time, until smooth. Add the cooled melted chocolates and beat until combined well.

Makes 1 - 9 x 13” cake or 3- 8” cakes