4 eggs
2 cups flour
1 1/2 cups powdered sugar
1/2 teaspoon baking soda
1 1/4 teaspoons cream of tartar
1/4 cup hot water
1 teaspoon vanilla

Beat the eggs with a rotary beater until they are thick and lemon colored. Sift the flour, powdered sugar, baking soda, and cream of tartar together several times. Sift these into the eggs and continue beating.

When all of the dry ingredients have been added pour in the boiling water, flavor with the vanilla, and pour into an ungreased sponge cake pan and bake in a preheated 350°F oven until a toothpick inserted in center of cake comes out clean.