K.,
Here is an edible recipe for you that doesn't contain peanut butter.
Cream Cheese Play Dough
8 oz. package of cream cheese
1/2 cup non-fat dry milk
1 tablespoon honey
crackers or bread slices
Combine cream cheese, milk and honey in a bowl and mix until well blended. Mold sculptures on was paper.
Storage: Unused portions MUST BE STORED in an airtight container and kept refrigerated! Because cream cheese is perishable, use the expiration date on the cream cheese package as your guide for how long you can keep this play dough.
Note: The shapes can then be placed on crackers or bread slices, decorated with edibles (celery or carrot slivers, raisins, dried fruit pieces, nuts, or seeds for a healthy snack... then eat!
You may also want to consider "pudding painting". You can take the already made containers of fat free pudding and have the kids "paint" their designs with their hands. Save the paintings and kids can eat while they go and/or eat what's leftover.