Microwave cakes?

So my Hungry Girl cookbook has a recipe for chocolate cakes, made in the microwave, that only have 130 calories. I was very skeptical because you just combine cake mix and lite, fat free vanilla yogurt and then cook in the microwave. They are topped with fat free Cool Whip mixed with lite Hershey's syrup. They are delicious! We have eaten them for dessert for the last two nights.