One of the blogs I follow is Crafting a Green World, and this is where I discovered the peanut butter play-dough recipe. We all love it. Almost tastes like peanut butter fudge.
2c powdered sugar
1c creamy peanut butter
It takes a bit for the powder to get mixed into the peanut butter and prevent it from sticking to everything, but it is worth the work.
I did discover that it keeps well in the fridge (and tastes better too).
Some fun things to do would be let your kids (or you) play with the play dough making small sculptures, cookie cutter cut outs, letters, numbers, etc., then placing them in the fridge for a quick treat later. The play-dough is rich, so you may want to stay with small pieces for a treat.
Hope you all have fun with this, we plan to make up another batch just before Halloween for party snacks :)