3/4 c. sifted flour
1/3 c. sifted cocoa powder
1 tsp. instant espresso or coffee powder (opt.)
1 1/2 c. sugar
12 room temperature egg whites
1 tsp. cream of tartar
1/4 tsp. salt
1 tsp. vanilla extract

Heat oven to 325 degrees. Combine flour, cocoa, espresso powder, if using 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, being careful not to over mix. Pour batter into an ungreased 10" tube pan. Run knife or spatula through batter to release any air bubbles.

Bake until a toothpick stuck into the center 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.