Ingredients
- 1 cup boiling water
- 3 oz unsweetened chocolate
- 8 T butter (1 stick)
- 1 tsp vanilla extract
- 2 cups granulated sugar
- 2 eggs, separated
- 1 tsp baking soda
- 1/2 cup sour cream
- 2 cups less 2 T all-purpose flour, sifted
- 1 tsp baking powder
- 2 T butter
- 3/4 cup semisweet chocolate chips
- 6 T heavy cream
- 1 1/4 cups confectioners' sugar (or as needed)
- 1 tsp vanilla extract
- Preheat oven to 350 degrees. Grease and flour a 10-inch tube pan. Knock out excess flour.
- In a large bowl, pour the boiling water over the chocolate and butter; let stand until melted. Stir in the vanilla and sugar, then whisk in egg yolks one at a time, blending well after each addition. Mix baking soda, and sour cream together and add to chocolate mixture.
- Sift together flour and baking powder; add to batter, mixing thoroughly.
- In a separate bowl, beat egg whites until stiff but not dry. Stir a quarter of the egg whites into the batter. Scoop remaining egg whites on top of batter and gently fold together.
- Pour the batter into prepared pan. Set in the middle rack of oven and bake 40-50 minutes, or until the edges have pulled away from the sides of the pan and a cake tester inserted into the center comes out clean. Cool cake in pan for 10 minutes; unmold and cool completely before frosting.
Chocolate Frosting
- Place all ingredients in a heavy saucepan over low heat and whisk until smooth.
- Cool slightly; add more sugar if necessary to achieve a spreading consistency.
- Spread on cake while frosting is still warm.
