My three-year-old son is starting a summer camp, and we need to pack him a lunch. He loves peanut butter and jelly sandwiches (PB&J), so we were all set for that to be a staple of his summer lunch diet, but unfortunately another child in the camp has a peanut allergy. So, PB&J is off the table (so to speak).
I'm wondering if there's some close substitute for peanut butter that would still work well in a sandwich with jelly, but is safe for those with allergies. (Analogous to soy milk for those who're lactose intolerant, I suppose.)