Heat oven to 375 degrees F. In medium bowl, sift flour and 3/4 sugar together; set aside. In large bowl, beat egg whites with cream of tartar, salt and vanilla until soft peaks form. Gradually add remaining 3/4 cup sugar, beating until stiff peaks form. Sift 1/4 of the flour mixture over egg whites; fold in. Repeat, sifting and folding 1/4 of the flour mixture at a time, until all flour mixture has been folded in. Pour into un-greased 10 inch tube pan. Bake at 375 degrees F for 35-40 minutes, until golden brown and cracks are dry. Immediately invert pan. Cool completely. Remove cake from pan. Slice in half horizontally. Set aside. In small bowl, combine thawed whipped topping, food coloring, lemon juice and grated lemon peel. Spread whipped topping over layers and sprinkle with berries. Garnish with lemon twists and berries. 12-16 servings.