Old-Fashioned Chocolate Layer Cake

A friend/coworker turned 30 today. To celebrate, I made a chocolate cake. I used the recipe below and also used the dreamy chocolate mousse for a couple of layers. It made an impressive looking and delicious cake. I didn't get any pictures. boo.

(I did use Nestle semisweet chocolate chips for the frosting, even though this was advised against. The only problem I had was that the frosting didn't get firm enough. This was easily solved by chilling it in the refrigerator).

Old-Fashioned Chocolate Layer Cake
-America's Test Kitchen
Serves 10-12

For the cake:
12 T (1 1/2 sticks) unsalted butter, very soft
1 3/4 cups unbleached all-purpose flour
4 oz unsweetened chocolate, coarsely chopped (I used semi-sweet chocolate and it was delicious too)
1/4 cup Dutch-processed cocoa powder
1/2 cup hot water
2 cups sugar, divided
1 1/2 t baking soda
1 t salt
1 cup buttermilk
2 t vanilla extract
4 large eggs, plus 2 large egg yolks

1. Adjust the oven rack to middle position. Heat oven to 350 degrees. Grease 2 9-inch round by 2-inch high cake pans with butter and dust with flour. Combine chocolate, cocoa powder, and hot water in a medium heatproof bowl; set bowl over saucepan containing 1 inch of simmering water and stir with a rubber spatula until chocolate is melted, about 2 minutes. Add 1/2 cup sugar to chocolate mixture and stir until thick and glossy, 1-2 minutes. Remove bowl from heat and set aside to cool.
2. Whisk flour, baking soda and salt in a medium bowl. Combine buttermilk and vanilla in a small bowl. In a bowl of a standing mixture fitted with the whisk attachment, whisk eggs and egg yolks on medium-low speed until combined, about 10 seconds. Add remaining 1 1/2 cups sugar. Increase speed to high, whisk until fluffy and lightened in color, 2-3 minutes. Replace mixer with paddle attachment. Add cooled chocolate mixture to egg mixture and mix on medium speed until thoroughly incorporated, 30-45 seconds, pushing to scrape down sides as needed. Add softened butter 1 tablespoon at a time, mixing 10 seconds after each addition. Add about 1/3 of flour mixture followed by half of butter milk mixture, mixing until incorporated after each addition (about 15 seconds). Repeat until thoroughly incorporated, mixing about 15 seconds after each addition. Remove bowl from mixer and fold batter once or twice with spatula to incorporate any remaining flour. Divide evenly between cake pans, smooth batter to edges of pan with spatula.
3. Bake cakes until toothpick inserted into center comes out clean with a few crumbs attached, 25-30 minutes. Cool cakes in pans for 15 minutes, then invert onto wire rack. Cool cakes at room temperature before frosting, 45-60 minutes.

(I baked these about a week before I needed them, wrapped them in plastic wrap and aluminum foil, and kept them in the deep freeze. I pulled them out early the morning I wanted to frost them).

For the frosting:
16 oz semisweet chocolate, finely chopped
8 T (1 stick) unsalted butter
1/3 cup sugar
2 T light corn syrup
2 T vanilla extract
1/4 t salt
1 1/4 cups cold heavy cream

1. Melt chocolate in a heatproof bowl set over a saucepan containing 1 inch of barely simmering water, stirring occasionally until smooth. Remove from heat and set aside. Meanwhile, heat butter in a small saucepan over medium-low heat until melted. Increase heat to medium; add sugar, corn syrup, vanilla, and salt and stir with a heat proof spatula until sugar is dissolved, 4-5 minutes. Add melted chocolate, butter mixture, and cream to clean bowl of a standing mixer and stir thoroughly to combine.
2. Place mixer bowl over ice bath and stir mixture constantly with spatula until frosting is thick and just beginning to harden against sides of bowl, 1-2 minutes (should be 70 degrees). Place bowl under mixer fitted with paddle attachment and beat on medium-high speed until frosting is light and fluffy, 1-2 minutes. Stir with rubber spatula until completely smooth.
3. To frost cake: (My adaptation) Cut each cake into two layers. Place one layer on serving platter. Spread about 1/4-inch thick layer of dreamy chocolate mousse evenly across layer. Place another layer of cake on top. Spread 1 1/2 cups frosting evenly on top of the cake. Place another layer of cake, another layer of mousse, and the final layer of cake. Then spread remaining frosting evenly over top and sides of cake. Cut into slices and serve. Store in the refrigerator. (Especially if you're making it in the heat and humidity of Kansas these days). :)