Place whites in bowl. Cover with plastic wrap and set on counter to bring to room temp (about 30min).
2
Combine cocoa and boiling water and stir until smooth. Add vanilla.
3
In another small bowl combine 3/4cup of the sugar, cake flour and salt.
4
Beat whites until foamy. Add cream of tartar. Continue to beat until soft peaks form. Gradually beat in remaining 1cup sugar until stiff peaks form.. Remove 1 cup of whites and add to cocoa mixture to lighten.
5
Slowly sift flour mixture over remaining egg whites and gently but quickly fold in.
6
Fold in cocoa mixture. Do not over mix.
7
Pour into pan. Run knife through to release air. Bake 40-45 mins in oven heated to 350 degrees.
8
Invert pan immediately after removing from oven. Use a skinny bottle to suspend pan. Cool completely. Run knife around edges to loosen from pan.
