Mamon (Sponge Cakes)

INGREDIENTS

• 2 1/2 cups all-purpose flour
• 1 cup white sugar
• 1 tablespoon baking powder
• 1 teaspoon salt
• 1/2 cup vegetable oil
• 8 egg yolks
• 2 tablespoons grated orange peel
• 1 teaspoon vanilla extract
• 1/3 cup orange juice
• 1/3 cup water
• 8 egg whites
• 1/2 teaspoon cream of tartar
• 1/2 cup white sugar