Sponge Cake

Ingredients (8)

• 6 large eggs, separated
• 1-1/2 cups all-purpose flour
• 1/2 teaspoon salt
• 1-1/2 cups sugar, divided
• 1/2 cup warm water
• 1 teaspoon vanilla extract
• 1/2 teaspoon cream of tartar
• Chocolate ice cream topping, optional