Preheat oven to 375°F. In large mixing bowl at high speed, beat whites with cream of tartar until foamy. Add 3/4 cup of the sugar, 2 tablespoons at time, beating constantly until sugar is dissolved and whites are glossy and stand in soft peaks. (Rub just a bit of meringue between thumb and forefinger to feel if sugar has dissolved.) Beat in flavorings. In medium bowl, sift together flour, remaining sugar, and salt. Sift about 1/2 cup of the flour mixture over whites and gently fold just until flour disappears. Repeat, folding in remaining flour mixture 1/2 cup at a time. Pour into ungreased 10 x 4-inch tube pan. Gently cut through batter with metal spatula.

Bake until top springs back when lightly touched with finger, about 30 to 40 minutes. Invert cake in pan on funnel or bottle neck. Cool completely, about 1 1/2 hours. With narrow spatula or knife, loosen cake from pan and gently shake onto serving plate. Serve with berries, whipped cream, and mint leaves, if desired.