* In a large bowl, combine the cake mix, water, yogurt, cocoa, egg whites and egg; beat on low for 30 seconds. Beat on medium for 2 minutes.
* Pour into a 10-in. fluted tube pan coated with cooking spray. Bake at 350° for 35-40 minutes or until a toothpick inserted near the center comes out clean. Cool for 10 minutes before removing from pan to a wire rack to cool completely. Dust with confectioners' sugar. Yield: 12 servings.