I'm British, so I'm not sure whether there's a cultural difference here... is fruitcake at Christmas a thing you do instead of Chrismas Cake / Christmas Pudding?
Christmas Cake:
It's a fruitcake under marzipan and icing.
Christmas Pudding:
This is the sixpence coin hidden in the pudding tradition that nobody does anymore:
And for the record,
THE PROOF IS NOT IN THE PUDDING,
THE PROOF OF THE PUDDING IS IN THE EATING!