Peanut Butter Popcorn Ingredients Peanut Butter Popcorn, adapted from Allrecipes 2 3.5 ounce packages microwave popcorn, popped (or the equivalent) 1/2 cup butter 3/4 cup brown sugar 1/4 cup peanut butter 20 large marshmallows 1/2 cup salted peanuts Instructions Pour popcorn and peanuts into a large bowl. Preheat oven to 250. Line cookie sheet