The "cupcake" is the hand gesture or pose where you use your hands to make a pedestal for your chin and smile. You can do this with both hands or do it with one hand and make a "half a cupcake".
Look at that girl doing the cupcake over there. She is trying to be real cute-sy.
You don't know what the cupcake is? You must be really basic.
When pronounced V-on-oof (noun): Ballin Ass Roommates
When pronounced V-on-oof-a (verb): The act of being Ballin Ass Roommates.
Jessie and I are so awesome. We are vionufe. We vionufed the hell out of that apartment.