Let eggs stand at room temperature for 30 minutes. Sift flour and salt; set aside.
In a large bowl, beat yolks until slightly thickened. Gradually add 1 cup sugar, beating until thick and lemon-colored. Blend in water and vanilla. Add dry ingredients to yolk mixture; mix well.
In another bowl, beat egg whites and cream of tartar on medium speed until soft peaks form. Gradually beat in remaining sugar, about 1 tablespoon at a time, on high until stiff glossy peaks form and sugar is dissolved. Fold a fourth of egg whites into the batter, then fold in remaining whites.
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 325° for 55-60 minutes or cake springs back when lightly touched. Immediately invert the pan; cool completely.
Run a knife around side and center tube of pan. Remove cake to a serving plate. Slice; if desired, drizzle with ice cream topping.