These are, obviously, REALLY easy. They're not sturdy and they don't keep - being what my children call "eating cookies" - and yet they have many, many things in their favour. We always, always have all of the ingredients, for one, and they're also gluten-free. You can also really dress them up - put a mini peanut butter cup in the center of each, or a few Smarties or M&Ms - and any half-way alert child can make them pretty much on their own.
one cup of peanut butter
1/2 cup of sugar (some recipes call for as much as one cup of sugar here, which I find painfully sweet. However, your taste buds may be different than mine, so I thought I'd mention it.)
Preheat the oven to 350. Mix together the sugar and egg and then mix in the peanut butter. You can either roll the dough in tablespoon-sized amounts into balls or just drop it by the tbsp on a cookie sheet lined with parchment paper.
Bake them for 6 to 9 minutes - you'll want to keep a close eye on them.