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

1. Preheat oven to 350 degrees. Grease and flour a 10 inch tube pan.

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

3. Mix baking soda and sour cream together and add to batter, mixing thoroughly.

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 the batter. Scoop remaining egg whites on top of the batter and gently fold together.

6. Pour batter into prepared pan. Bake on middle rack 40-50 minutes. Edges should pull away, toothpick should come out clean. Cool for 10 minutes, unmold and frost.