Grease and flour a 15-1/2 x 10-1/2 x 1-inch jelly roll pan. Preheat oven to 350 °F.

Sift together first 4 ingredients. In large mixer bowl combine egg whites and water. Beat on high speed until frothy. Gradually beat in 1/2 cup granulated sugar; continue beating until glossy.

In small mixer bowl beat egg yolks until thickened, 3 minutes. Gradually beat in 1/3 cup sugar. Add vanilla extract and beat 2 minutes longer. Fold into egg whites, then fold in dry ingredients just until blended. Do not over mix. Spread batter evenly in pan. Bake 12 to 15 minutes, until lightly browned and center springs back when lightly touched with finger.

Meanwhile, sprinkle a dish towel or a 24 x 13-inch reusable wipe with confectioners' sugar. Turn cake out onto towel. While cake is still hot, roll up cake and towel together (rolling up from long end). Let stand 1 minutes; unroll to allow steam to escape, then re-roll with towel and let cool on wire rack.

Unroll and spread with ice cream to within 1/2 inch of edges. Re-roll (no towel this time). Trim off ends. Cover and freeze until firm and ready to serve. If desired, serve with Hot Fudge Sauce.