Good-Cooking - Delta Mocha Chiffon Cake

Ingredients

• 3/4 cup boiling water
• 1/2 cup cocoa
• 1 teaspoon instant coffee granules
• 1 3/4 cups cake flour
• 1 3/4 cups granulated sugar
• 1 1/2 teaspoons baking soda
• 1/2 teaspoon salt
• 8 large eggs, separated
• 1/2 cup vegetable oil
• 2 teaspoons vanilla extract
• 1/2 teaspoon cream of tartar