Preheat oven to 325 °F. Grease a 10 x 14 x 2- inch baking pan and line with waxed paper.
Sift dry ingredients (except sugar) together. Cream butter. Add 2 cups of the sugar alternately with egg yolks, blending well after each addition. Fold in flour mixture alternately with water and milk.
Beat egg whites until frothy. Add the remaining 1/2 cup sugar and beat until stiff but not dry. Fold egg yolk mixture into egg white mixture.
Spread evenly on prepared pan and bake for 30 - 40 minutes. Cool on rack. Lift out cake, holding onto waxed paper. Serve as is or if desired, brush with Orange Liquor Syrup. Serve with whipped cream or vanilla ice cream with fruits.