1 (18 1/4 ounce) box light yellow cake mix
1 (1 ounce) box instant sugar-free pistachio pudding mix
1 (8 ounce) container nonfat plain yogurt
3 egg whites
1 teaspoon vanilla extract
1 cup diet lemon-lime soda

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
1 1/3 cups cold skim milk
1 (1 ounce) package instant sugar-free pistachio pudding mix
2 cups light whipped topping

Combine milk and dry pudding mix in a mixing bowl; beat on low for 2 minutes. Fold in whipped topping. Spread over cake. Store in the refrigerator.

Diabetic Exchange: 2 starch