The only problem we encountered was this. . .
What happened was the cake rose so high that it hit the metal rack, which knocked the cup over. At first I didn't get what happened. We heard this loud bang and then I opened the microwave to see the cup knocked over and the cake almost completely out of the cup. I just thought it exploded and popped out. Duh, Holly-the rack! It actually took me a minute to figure that out. . .cuz I'm slow sometimes. :)
Here are the kids enjoying their treat, along with icecream on the side topped with whip cream(because I believe in packing in the sugar!) It was heavenly. Thanks Melissa for the idea!