A cupcake is a person who...
...from outward appearance you would assume they are tough, but on the inside they are soft.
...can be very sweet.
...is the perfect size, just the right amount of everything.
...is also cute yet delicious.
...people are always in the mood to hang out with them, just like people are always in the mood to have cupcakes.
...people never get sick of.
“I think Richy’s nickname should be Cupcake. It describes him perfectly.”
“Hey Cupcake! What’s up?” http://www.urbandictionary.com/define.php?term=cupcake
Allerdings wäre mir 'cupcake' als Name für ein Haustier geläufiger - wenn es auch nicht allzu häufig vorkommt.