3/4 c. sifted cake flour
1 tsp. instant coffee (optional)
12 room temperature egg whites
1/4 tsp. salt
1/3 c. sifted cocoa powder
1 1/3 c. sugar
1 tsp. cream of tartar
1 tsp. vanilla extract

Heat oven to 325 degrees. Combine flour, cocoa, coffee powder and 3/4 cup of the sugar. Beat whites with cream of tartar and salt until whites hold soft peaks. Gradually beat in remaining 3/4 cup sugar and continue beating until whites hold stiff peaks. Beat in vanilla. Gently fold in flour mixture.

Pour batter into an ungreased 10-inch tube pan. Run a knife or spatula through batter to release any air bubbles. Bake until a toothpick comes out clean, about 45 minutes. Invert pan over a bottle and cool completely, about 1 hour. Run a knife around edge of pan to release cake.