Step 1

Preheat oven to 350 degrees F

Step 2

In a metal or glass bowl, beat egg whites, 1/2 cup sugar, and cream of tartar until stiff peaks form.

Step 3

In a separate bowl, beat egg yolks, water, remaining sugar, vanilla, and oil.

Step 4

Whisk flour and baking powder in another bowl.

Step 5

Mix flour and yolk mixture.

Step 6

Gently fold the flour and yolk into the egg whites.

Step 7

Pour into an ungreased angel food tin and bake for 40-50 minutes or until cooked through. The cake should spring back when lightly tapped (not sink).

Step 8

For best height, cool the cake in the tin turned upside down, but be careful of the cake falling out of the tin. Cake can be served and stored at room temperature.