• Place egg whites in a large bowl; let stand at room temperature for 30 minutes. Sift together the flour, 1 cup sugar and cocoa twice; set aside.
• Add the cream of tartar, vanilla and salt to the egg whites. Beat on medium speed until soft peaks form. Gradually beat in remaining sugar, about 2 tablespoons at a time, on high until stiff glossy peaks form and sugar is dissolved. Gradually fold in flour mixture, about 1/2 cup at a time.
• Gently spoon into an ungreased 10-in. tube pan. Cut through batter with a knife to remove air pockets.
• Bake on the lowest oven rack at 350° for 40-50 minutes or until lightly browned and entire top appears dry. Immediately invert pan; cool completely, about 1 hour.
• Run a knife around side and center tube of pan. Remove cake to a serving plate. For glaze, in a microwave-safe bowl, melt chocolate chips and cream. Stir until smooth. Drizzle over cake.
• Yield: 12 servings.