Preheat oven to 350

Coat a 9 x 13 pan with cooking spray

Stir lemon peel into cake batter and pour into prepared pan

Bake 35 to 40 minutes or until toothpick comes out clean

In medium bowl, beat egg whites and cream of tarter u til stiff peaks form

Gradually beat in sugar until stiff peaks form again

Spoon over cake and form peaks with spatula

Bake 12 to 15 minutes until golden