Chocolate Angel Cake

This was a huge hit at Sierra-Lynn's birthday party last year. She loved it so much that she wants to have it again this year.

Chocolate Angel Cake
Makes 12 to 16 servings

Ingredients:
1 1/2 cup powdered sugar
1 cup cake flour
1/4 cup baking cocoa
1 1/2 cup egg whites (about 10 eggs)
1 1/2 tsp cream of tartar
1/2 tsp salt
1 cup sugar
FROSTING:
1 1/2 cups whipping cream
1/2 cup sugar
1/4 cup baking cocoa
1/2 tsp salt
1/2 tsp vanilla extract
Directions:
Sift together powdered sugar, flour and cocoa three times; set aside. 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. Spoon into an ungreased 10 inch tube pan. Carfully run a metal spatula or knife through batter to remove air pockets. Bake on lowest oven rack at 375 degrees for 35 to 40 minutes or until the top springs back when lightly touched and cracks feel dry. Immediately invert pan; cool completely. Run a knife around edges and center tube to loosen; remove cake. In a mixing bowl, combine the first five frosting ingredients; cover and chill for 1 hour. Beat until stiff peaks form. Spread over top and sides of cake. Store in refrigerator.