dark-chocolate cake with ganache frosting

the goods:

cake:
1 cup (2 sticks) unsalted butter, room temperature, plus more for pans
1/2 cup unsweetened Dutch-process cocoa powder, plus more for pans
2 cups all-purpose flour
1/2 teaspoon baking powder
1/2 teaspoon baking soda
1/2 teaspoon salt
1 and 1/2 cups packed light-brown sugar
2 large eggs plus 2 large egg yolks, room temperature
6 ounces bittersweet chocolate, melted
1 teaspoon pure vanilla extract
1 cup buttermilk

ganache:
2 cups heavy cream
1/2 cup confectioners' sugar
1/8 teaspoon salt
1 pound (16 ounces) bittersweet chocolate, roughly chopped



Preheat oven to 350 degrees. Butter 2 8-inch round cake pans; dust with cocoa, tapping out excess. Line bottom of each pan with a round of parchment paper; set aside.



In a medium bowl, whisk together flour, cocoa, baking powder, baking soda, and salt; set aside.



In a large bowl, using an electric mixer, beat butter and sugar until light and fluffy. Add eggs and yolks, one at a time, beating well after each addition; beat in chocolate and vanilla. With mixer on low, alternately add flour mixture in three parts and buttermilk in two, beginning and ending with flour mixture.



Divide batter between prepared pans; smooth tops. Bake until a toothpick inserted in center of cake comes out clean, 35 to 40 minutes.



While cake is baking, make ganache. In a heavy saucepan, bring heavy cream, confectioners' sugar and salt to a boil. Remove from heat; add bittersweet chocolate, and let stand, without stirring, for 1 minute. Whisk just until combined. Refrigerate, stirring occasionally, until spreadable, about 1 hour.



Remove cakes from oven, cool in pans 15 minutes; run a knife around edge of each pan, and invert cakes onto a wire rack to cool completely.



Place one cake on serving platter. Place pieces of parchment or wax paper beneath edges of cake to protect platter from frosting.



Spread top of cake with 1/3 of the ganache.



Place second cake on top, and spread with remaining ganache over top and sides of cake. Slide parchment pieces out from under cake to reveal a clean platter!



Slice and serve with a tall glass of milk!