less 2 tablespoons of flour
semi-sweet chocolate chips
1Preheat oven to 350 degrees.
3Pour boiling water over chocolate and butter; let stand until melted.
4Stir in vanilla and sugar, then whisk in egg yolks, one at a time, until blended well.
5Mix soda and sour cream and whisk into chocolate mixture.
6Mix flour and baking powder well, and add to batter, mixing thoroughly.
7Beat egg whites until stiff but not dry.
8Stir in a quarter of the egg whites thoroughly into the batter.
9Scoop the remaining egg whites on top of the batter and gently fold in.
10Pour batter into prepared pan.
11Set on the middle rack of the oven and bake for 40-50 minutes or until the edges have pulled away from the pan and the cake tester inserted comes out clean.
12Cool in pan for 10 minutes; unmold and cool completely before frosting.
13For Chocolate Frosting: Place all ingredients in a heavy saucepan and whisk until smooth over low heat.
14Cool slightly; add more sugar if necessary.
15Spread on cake while frosting is still warm.