1. Combine chocolate, butter and water in top of double boiler.

2. Heat chocolate mixture over simmering water until chocolate and butter melt.

3. Remove from heat.

4. Cool. Sift flour, baking soda and salt into large bowl.

5. Beat eggs with sour cream until blended in medium-size bowl.

6. Beat in sugar and vanilla.

7. Stir in cooled chocolate mixture.

8. Beat into flour mixture, half at a time, just until smooth.

9. Batter will be thin.

10. Pour evenly into 2 greased anf floured 8 cake pans.

11. Bake at 350 for 40 minutes or until center springs back when lightly pressed with finger tip. Cool in pans on wire racks.

12. Loosen edges with knife and turn out onto racks.

13. Stack cakes, frosting between layers, using 1/4 of frosting.

14. Frost top and sides with remaining frosting, making deep swirls w/spatula.

15. If chocolate drizzle is desired, melt 1 square chocolate with 1 tablespoon butter in cup set in hot water.

16. Stir until smooth.

17. Drizzle over top of cake, letting mixture drip down sides.

18. Fluffy White Frosting: Combine egg whites, sugar, cream of tartar, salt and water in top of large double boiler.

19. Beat until blended.

20. Place top over simmering water.

21. Cook, beating constantly with electric or rotary beater, about 7 minutes or until mixture stands in firm peaks.

22. Remove from water.

23. Stir in vanilla.

24. -----.