Good-Cooking - Perfect Sponge Cake

Ingredients

• 1 1/4 cups sifted cake flour
• 1/4 teaspoon baking powder
• 6 eggs
• 3/4 teaspoon cream of tartar
• 1 1/2 cups granulated sugar
• 1/3 cup cold orange juice
• 1/4 teaspoon salt
• 1 teaspoon vanilla extract