Sift together flour, baking powder, and salt. Set aside.
Beat egg whites (at room temperature) until foamy. Gradually add 1/4 cup plus 2 tablespoons sugar, 1 tablespoon at a time, beating until stiff peaks form. Set aside.
Beat egg yolks in a large mixing bowl until thick and lemon colored. Gradually add remaining sugar, beating 5 minutes or until light and fluffy. Add water and vanilla; beat well. Fold egg whites into yolk mixture. Gradually fold in flour mixture, 1/4 cup at a time, until well blended.
Pour batter evenly into a waxed paper-lined 15- x 10- x 1- inch jellyroll pan. Bake at 375° for 12 to 15 minutes.
Sift 2 tablespoons powdered sugar in a 15- x 10-inch rectangle on a linen towel. When cake is done, immediately loosen from sides of pan, and turn out onto powdered sugar. Peel off waxed paper. Starting at narrow end, roll up cake and towel together; let cool on a wire rack, seam side down.
Beat whipping cream until foamy; gradually add remaining powdered sugar, beating until soft peaks form.
Unroll cake, and remove towel. Spread with half of sweetened whipped cream. Top with 2 cups strawberries; re-roll cake. Spread outside of cake roll with remaining whipped cream. Garnish with remaining strawberries. Chill until serving time. Cut into slices to serve.