In a medium bowl, beat egg whites with electric mixer on high speed until stiff peaks form. Make sure the bowl and beaters are clean and the egg whites have no speck of yolk in them.

In a 1 quart saucepan, whisk together sugar, corn syrup and water until well blended. Cover and heat to a rolling boil over medium heat. Uncover and boil 4-8 minutes without stirring, until a candy thermometer inserted into mixture reaches 242 F. (It will spin into a 6 inch thread when you dip a spoon into it and let it stream off the spoon.)

Pour the hot sugar mixture slowly in a thin stream into the egg whites, beating constantly on medium speed.

Once sugar syrup is all incorporated, add vanilla and beat on high speed about 10 minutes, or until stiff peaks form.

Frost sides and top of cake in decorative swirls.