Heat oven to 375°F.

Combine flour and 3/4 cup sugar in bowl; set aside.

Beat egg whites, cream of tartar, vanilla and salt at medium speed in another bowl, scraping bowl often, until soft peaks form.

Increase speed to high. Beat, adding remaining 3/4 cup sugar, 2 tablespoons at a time and scraping bowl often, until well mixed.

Spoon flour mixture over egg whites, 1/4 cupful at a time. Gently stir just until combined.

Pour batter into ungreased 10-inch tube pan. Cut gently through batter with metal spatula.

Bake 30-40 minutes or until cracks feel dry and top springs back when touched lightly.

Invert pan on heat-proof funnel or bottle; cool completely. Remove from pan.