A.B.
I just made these last night and my kids will decorate them tonight. They're great because all they need is green frosting and m&m's so they should look good no matter how old the decorator is!
http://familyfun.go.com/recipes/tasty-trees-816815/
Another mom last year gave me the idea to put storebought peanut butter cookie dough into a mini muffin tin (roll into balls), bake at 350 for 10 minutes, then push an unwrapped mini peanut butter cup in each one as soon as they come out of the oven. Easy and kids love them, as long as there are no peanut allergies.
I've made them w/ my own peanut butter cookie dough too.