I love meringues and thought the kids would think it would be fun to help me make meringue mushrooms. They are very easy to make but take a long time to cook so I did that part on my own and enlisted the kids when it was time to attach the stems to the caps with chocolate. They enjoyed the process, and did a good job assembling them, messy finger prints and all.
One note about the meringues: The cooking time varies enormously so they are not a good thing to make if you are on a deadline. In fact, I was planning on serving these at our New Year's Eve party but they were not done in time. We ended up assembling them as an activity on New Year's Day instead. We used this recipe from Martha Stewart. One option that works really well if the meringues are still sticky after several hours is to turn the oven off but leave the meringues inside overnight. The slow residual heat tends to dry them out pretty well without any danger of browning.