Categories: Chocolate, Cakes/choc. 
      Yield: 12 servings 
  
      1 c  Boiling water                       1 ts Baking soda 
      3 oz Unsweetened chocolate             1/2 c  Sour cream 
      8 tb Sweet butter (1 stick)              2 c  Less 2 T flour 
      1 ts Vanilla                             1 ts Baking powder 
      2 c  Sugar                                    Chocolate frosting* 
      2    Eggs, separated                          *see below 
  
  1.  Preheat oven to 350F. Grease a 10" tube pan. 
   
  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, until 
  blended well. 
   
  3. Mix soda and sour cream and whisk into chocolate mixture. 
   
  4. Mix flour and baking powder well, and add to batter, mixing thoroughly. 
   
  5. Beat egg whites until stiff but not dry. Stir in a quarter of the egg 
  whites thoroughly into the batter. Scoop the remaining egg whites on top of 
  the batter and gently fold in. 
   
  6. Pour batter into prepared pan. Set on the middle rack of the oven and 
  bake for 40-50 min. or until the edges have pulled away from the pan and 
  the cake tester inserted comes out clean. Cool in pan for 10 minutes; 
  unmold and cool completely before frosting. 
   
  =============================Chocolate Frosting====================== 
   
  2   T   sweet butter                    3/4 c semisweet chocolate chips 6 T 
  heavy cream                     1 1/4 c confectioners sugar 1 t vanilla 
   
  Place all ingredients in a heavy saucepan and whisk until smooth over low 
  heat. Cool slightly; add more sugar if necessary. Spread on cake while 
  frosting is still warm. 
   
  Source:  Silver Palate Cookbook