Here's a sweet idea: Use leftover candy to create a make-it-yourself ice cream sundae party. Simply chop the treats into bits, and set them out in small bowls so everyone can choose a favorite topping. Our assortment includes candy sticks, toffee bars, and chocolate-covered almonds, but any candies or nuts will work well.
Sundae Social
Martha Stewart Living, January

Every year we have a large outdoor July 4th Party "Red, White And Boone" (our last name) we invite everyone to bring their own homemade ice cream and the winner gets added to the plaque each year. We have every flavor you can imagine including carrot cake, apple pie, orange, and even cucumber. It is a whole lot of fun and a tasty treat!
I have 2 teens and this would be a great idea for a Christmas holiday get-together while school is out.