As it turns out, it does. Not only that, but it answers why I kept feeling like the cake-in-a-mug didn't exactly taste like a regular cake. From what I can tell, this recipe is basically pancake-in-a-mug. At least flavour-wise. That, and the need for milk to drink wasn't just because of the chocolate. These cakes are asoundingly dry. Which is what you get for using the moisture boiling away as your primary method of rising, I suppose.
It's also horrendously dense. I'm not sure why, but this thing is far denser than the chocolate one. Not certain how I can fix that, but I have hopes that it may be solved in future iterations. It wasn't quite to the point where I needed a knife in order to eat it, but it was quite close. I expect to make the rainbow variant either tonight or tomorrow night. There will be pictures.