Actually in the Seventh Doctor serial "The Happiness Patrol", there is a villain called the Kandy Man, a sentient creature made out of candy. There's a picture here: http://en.wikipedia.org/wiki/The_Happiness_Patrol

Somehow, after encountering that nasty, I doubt the Doctor would want anything to do with any sentient candy! :D

Back OT, lovely story, and in the spirit of the season! :)