That's a hard question, but if you have the time you could make some different candies and call them things from the book.

Cockroach clusters (You could make like a pecan cluster with dark chocolate chunks to be the cockroaches)
Butterbear, you could bring warm apple cider or something and call it butterbear
*thinks*

They always have lots of typical British food at the Hogwarts feasts, so you could make some of those type dishes with pudding and treacle tarts and stuff.

Hope I helped!