Bring egg whites to room temp. sift flour, powd. sugar, cocoa powder, & cinnamon thoroughly. set aside. in lg. mixing bowl, beat egg whites, cream of tartar, & vanilla with an electric mixer on med. speed till soft peaks form. gradually add sugar, 2 Tbsp at a time, beating on high speed till stiff peaks form. sift 1/4 of floyr mixture over beated mixture, and fold in gently. Repeat, folding remaining mixture in by fourths. pour into ungreased tube pan. bake on lowest rack of oven at 350 deg. for 40-45 min or till top springs back when lightly touched. immediately invert and allow to cool