Yep, you're reading right. I took one can of diet lemon-lime soda and one box of cake mix and added nothing else and wound up with a cake (I baked it of course!).
I don't have a picture of the cake, because it was eaten so quickly by my husband and co-workers.
This was another Hungry Girl creation; however, I used completely different ingredients because it was what I had in the pantry.
This week I'm going to try diet root beer with yellow cake. I'll let you know how it turns out!
(Her list of possibly cakes are not on her website; it was part of the subscribed email list. There are a couple listed at this link, but it's far from all the possibilities!)