Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
  8             ounces  semi-sweet chocolate
  3               cups  flour
  1           teaspoon  baking powder
  1           teaspoon  baking soda
     1/2           cup  unsalted butter
  1                cup  sugar
  3                     egg
  1         tablespoon  vanilla
  2               cups  sour cream

Preparation:

Heat chocolate in the top of a double-boiler, until melted sift together flour, baking powder, and baking soda, set aside cream together butter and sugar, until light and fluffy beat eggs, one at a time, into butter mixture beat in vanilla and sour cream gradually beat in dry ingredients (mixture will be quite thick) stir 1 cup mixture into melted chocolate spoon 1/2 of light colored batter into a greased 12-inch springform pan cover with half of dark colored batter spoon remaining light colored batter on and top with remaining dark colored batter cut with a knife to swirl slightly smooth top bake @ 325 degrees for 50-60 minutes remove from oven, cool for 2-3 hours before removing springform serve at room temperature

Nutritional Information:

261 Calories (kcal); 13g Total Fat; (44% calories from fat); 4g Protein; 32g Carbohydrate; 63mg Cholesterol; 136mg Sodium