Trying to find a book I read when I was a child (long time ago). No idea of the name or author. Please help!?

A long time ago I read a childrens book and I am trying to track it down several years later (25 ish SCARY). From what I can remember it was set around Christmas time and was about a girl who kept on sneaking downstairs from her room, presumably on Chrismtas Eve to eat a present which was a box of chocolate kittens, bunnies or something along those lines. Yet again from what I can remember she made herself sick and was ill on Christmas Day. I'm struggling to remember anymore information although if there is anyone out there that this sounds familiar to PLEASE let me know. Thank you!