In small bowl, combine and beat well the flour, cocoa, baking powder, 1 cup sugar, egg yolks, water, and vanilla. In a large bowl, beat until stiff, egg whites, salt, and cream of tartar. Gradually add the 1/2 cup sugar. Continue beating until very stiff. Then fold chocolate mixture into egg white mixture. Turn into tube pan. Bake at 325 degrees F for 1 hour.
By Robin from Washington, IA