1 c. boiling water
3 oz. unsweetened chocolate
8 tbsp. (1 stick) sweet butter
1 tsp. vanilla extract
2 c. granulated sugar
2 eggs, separated
1 tsp. baking soda
1/2 c. dairy sour cream
2 c. less 2 tbsp. unbleached, all-purpose flour, sifted
1 tsp. baking powder
Chocolate frosting (recipe follows)

1. Preheat oven to 350 degrees. Grease and flour a 10-inch tube pan. Knock out excess.

2. Pour boiling water over chocolate and butter, let stand until melted. Stir in vanilla and sugar, then whisk in egg yolks, one at a time, blending in after each addition.

3. Mix baking soda and sour cream and whisk into chocolate mixture.

4. Sift flour and baking powder together and add to batter, mixing thoroughly.

5. Beat egg whites until stiff but not dry. Stir a quarter of the egg whites thoroughly into batter. Scoop the remaining egg whites on top of the batter and gently fold together.

6. Pour batter into prepared pan. Set on the middle rack of the oven and bake for 40-50 minutes, or until the edges have pulled away from side of pan and cake tester inserted into the center comes out clean. Cool in pan for ten minutes, unmold and cool completely before frosting. 12 portions

CHOCOLATE FROSTING:

2 tbsp. sweet butter
3/4 c. semi-sweet chocolate chips
6 tbsp. heavy cream
1 1/4 c. sifted confectioner's sugar or as needed
1 tsp. vanilla extract

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.