Try this
1 3/4 cup cake flour
1/2 tsp. salt
2 1/2 tsp. baking powder
2 eggs, separated and whites beaten until stiff
1 stick butter, softened
1 cup sugar
1 tsp. vanilla extract
1/2 cup vitamin water
Instructions:
Preheat oven to 350°. Mix flour, salt, and baking powder together; set aside. Beat egg whites until stiff; set aside. Mix butter, sugar, egg yolks, and vanilla in a mixing bowl until smooth. In a separate bowl, gradually add dry ingredients to creamed ingredients, slowing adding water until blended. Then, fold in the stiff egg whites. Fill cupcake liners until 1/2 full. Bake in a preheated oven for 15 minutes, or until a toothpick comes out clean. Cool cupcakes completely.