1 ½ cups confectioner's sugar
1 cup cake flour
¼ cup cocoa
1 ½ cups egg whites (about 10 eggs)
1 ½ tsp cream of tartar
½ tsp salt
1 cup sugar

Frosting:
1 ½ cups heavy whipping cream
½ cup sugar
¼ cup baking cocoa
½ tsp salt
½ tsp vanilla

1. Sift together confectioner's sugar, flour, and cocoa 3 times. Set aside.

2. In a mixing bowl, beat egg whites, cream of tartar, and salt until soft peaks form. Add sugar, 2 tbsp at a time, beating until stiff peaks form. Gradually fold in cocoa mixture, about a fourth at a time.

3. Spoon into an ungreased 10-in. tube pan. Carefully run a metal spatula or knife through batter to remove air pockets. Bake on lowest oven rack at 375 degrees for 35 - 40 minutes or until the top springs back when lightly touched and cracks feel dry.

4. Immediately invert pan; cool completely. Run a knife around edges and center tube to loosen; remove cake.

5. In a mixing bowl, combine the frosting ingredients. Cover and chill for 1 hour. Beat until stiff peaks form. Frost top & sides of cake. Store in refrigerator.