In a large mixing bowl, beat egg whites with cream of tartar at high speed until foamy. Add 3/4 cup of the sugar, 2 Tbsp. at a time, beating constantly until sugar is dissolved and whites are glossy and stand in soft peaks. Beat in flavorings.
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 in preheated 375°F oven 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. Top with fruit or frost, if desired.
Chocolate variation: Omit almond extract and increase vanilla to 2 teaspoons. Reduce flour to 2/3 cup and sift in 1/3 cup unsweetened cocoa. Prepare batter and bake as above.