Cake: In a mixing bowl, combine dry cake and pudding mixes, yogurt, egg whites
and vanilla; beat on low speed for 1 minute. Gradually beat in lemon-lime soda.
Pour into a 13 x 9-inch baking pan coated with nonstick cooking spray.
Bake at 350 degrees F for 20 to 25 minutes or until a wooden pick inserted near
the center comes out clean. Cool.
Frosting: Combine milk and dry pudding mix in a mixing bowl; beat on low for
2 minutes. Fold in whipped topping. Spread over cake.