1. Bring egg whites to room temperature, about 1 hour.
2. Meanwhile,sift flour, cocoa, powdered sugar, and cinnamon together three times. Set aside.
3. In a large mixer bowl, beat the egg whites, cream of tartar, and vanilla with an electric mixer on medium speed until soft peaks form. Gradually add the sugar, 2 Tablespoons at a time, beating on high speed until stiff peaks form. Transfer to a larger bowl if needed.
4. Siftabout 1/4th of the flour mixture over the beaten egg whites. Fold in gently. Repeat, folding in the remaining flour mixture in fourths.
5.Pour into ungreased 10-inch tube pan. Bake on the lowest rack in the ovenat 350°F for 40-45 minutes or until the top springs back when touched.
6. Immediately invert cake (leave in pan); cool thoroughly. Loosen sides of cake from pan; remove.
This is GOOD!!!!!!
* 10-12 eggs can be used to make about 1/2 cup egg whites