1. Preheat oven to 350F.

2. Lightly grease a 10 cup pan with a removable bottom and dust with cocoa powder.

3. Resift the cake flour five times with the cocoa powder and 1/3 cup granulated sugar.

4. Using 1/4 of the egg whites at a time, whip all the whites until foamy.

5. (See below for egg white notes.

6. ) Add the cream of tartar when all 11 egg whites are foamy.

7. Continue to whip the egg whites, adding 1/4 cup sugar, 1 tablespoon at a time.

8. Stir the vanilla extract and chocolate flavor into the beaten egg whites.

9. Sift 1/4 of the flour mixture into the batter and fold gently.

10. Repeat until finished with the flour.

11. Pour the batter into the prepared tube pan. Gently move a knife through the batter to remove air pockets.

12. Bake in the preheated oven for 45 minutes.

13. Invert pan and let cool for 1 1/2 hours.

14. Remove from pan and drizzle with vanilla glaze.

15. Beating Egg Whites: Use a deep glass bowl and a thin wire whisk.

16. Do not use an aluminum or plastic bowl.

17. Since this recipe calls for cream of tartar, do not use a copper bowl.

18. The egg whites whould be 75F in temperature and should contain no egg yolk.

19. For glaze, stir all ings.

20. until smooth and pour over cake.