Chocolate Angel Food Cake With Chocolate Buttercream Frosting

I hear this is Delicious! This is the chocolate version of the white angel food cake I posted from the Rose's cookbook.

• Ready In: 2 hrs
• Serves: 4-6
• Yields: 1 cake

Ingredients

• CAKE

• 1  cup  sifted cake flour
• 4  tablespoons  cocoa
• 1 1⁄3 cups sugar, divided
• 1⁄8 teaspoon salt
• 11  egg whites
• 1  teaspoon cream of tartar
• 1  teaspoon vanilla

• FROSTING

• 2  egg whites
• 3  tablespoons water
• 1  teaspoon vanilla
• 1⁄4 teaspoon cream of tartar
• 1  cup sugar
• 1  cup sweet butter
• 1⁄4 cup  sifted  cocoa
• 1⁄8 teaspoon salt

Directions

1. CAKE:
2. Preheat oven to 350 degrees Fahrenheit.
3. Sift flour, cocoa and 1/3 cup sugar 5 times.
4. Add salt to egg whites and beat until stiff.
5. Add cream of tartar to the egg whites and the balance of the sugar gradually, 1 Tablespoon at a time, beating until very stiff.
6. Add vanilla.
7. Fold in the flour mixture a little at a time.
8. Pour batter into a 9" tube pan and bake for 15 minutes at 350 degrees Fahrenheit.
9. Reduce heat to 300 degrees Fahrenheit to finish baking.
10. Total baking time is about 1 hour.
11. FROSTING:
12. Combine egg whites, water, vanilla, cream of tartar, and sugar in upper part of a double boiler.
13. Mix well, beat over heat until mixture stands up in peaks.
14. If electric beater is used, bring water in lower part of double boiler to a rapid boil and beat for about 2 minutes.
15. Remove from stove and beat 3 or 4 minutes at high speed until it stands in high peeks. Be careful not to scrape beater against bottom of pan as it will darken the mixture.
16. Allow the mixture to cool, keeping it covered with a damp cloth to prevent a crust from forming.
17. Cream butter thoroughly; add cocoa (use more cocoa if more intense flavor is desired) and salt.
18. Have marshmallow mixture and butter at about same temperature and consistency before combining them (otherwise, frosting will have a tendency to separate or curdle).
19. Keep cool, not cold. If frosting should curdle, add about 2 Tablespoons hot melted butter and beat well.
20. Frost top and sides of cake.