Cakes that will keep for several days....

I'm visiting my son for the first time since he left for Uni at the start of September and would love to take him a cake he can keep in a tin for a few days. He's not a big fruit cake fan, so I am wondering what might be another nice option that will wrap and keep for several days? He is a big chocolate fan (aren't we all?!), but any suggestions would be welcomed. Thank you :)