I don’t remember where I found this, but it was a huge hit at our house. We halve this recipe.
2 (3.5 oz pkgs) microwave popcorn, popped OR 1 cup unpopped popcorn, POPPED
1/2 cup butter
3/4 cup brown sugar
1/4 cup peanut butter
20 large marshmallows
Combine everything but the popcorn and micro and stir, micro and stir until melted and combined.
Stir in popcorn quickly.