- 3 ounces semisweet chocolate, chopped
- 1 1/2 sticks (3/4 cup) unsalted butter, softened
- 1 1/2 cups granulated sugar
- 1/2 cup firmly packed light brown sugar
- 1 3/4 cups sour cream
- 1 1/2 teaspoons vanilla extract
- 3 large eggs
- 2 cups all-purpose flour
- 1/2 cup unsweetened cocoa powder (not Dutch-process)
- 1 teaspoon baking soda
- 1/2 teaspoon salt
- 3 ounces semisweet chocolate, chopped
- 2 cups sour cream
- 1 cup heavy cream
- 1 cup confectioners' sugar
- 1 teaspoon vanilla extract
- 3 ounces semisweet chocolate, chopped
- 2 tablespoons unsalted butter
- 1 cup semisweet chocolate chips and 1/2 cup semiseet chocolate shavings, shaved with a vegetable peeler from a bar of chocolate, for coating side of cake
- Preaheat oven to 375°F. Butter and flour two 9- by 2-inch round cake pans, knocking out excess flour.
- In a double boiler or a metal bowl set over a pan of barely simmering water melt chocolate, stirring until smooth, and cool.
- In a large bowl with an electric mixer beat together butter and sugars until light and fluffy. Bet in sour cream and vanilla until combined. Add eggs, 1 at a time, beating well with after each addition.
- In a bowl whisk together flour, cocoa powder, baking soda, and salt and gradually add to sour cream mixture, beating until just combined. Beat in chocolate until batter is just combined and divide between pans.
- Bake layers in middle of oven until a tester comes out clean, about 30 minutes. Cool layers in pans on rack 10 minutes and invert onto racks to cook completely.
- In a double boiler or a metal bowl set over a pan of barely simmering water, melt chocolate, stirring until smooth, and cool to room temperature. In a large bowl with an electric mixer beat together sour cream, heavy cream, confectioners' sugar, and vanilla until thickened. Beat in chocolate until combined.
- In a double boiler or a metal bowl set over a pan of barely simmering water, melt chocolate and butter, stirring until smooth, and cool.
- With a long serrated knife halve cake layers horizontally. Stack layers on a cake plate, spreading 1 cup filling/frosting between each layer. Spread side of cake with remaining filling/frosting.
- Pour glaze on top of cake, spreading to just cover top, and coat side with chocolate chips and shavings, pressing them in gently.