Microwave caramel corn

1 large bag microwave popcorn
1 stick butter
1/2  C. brown sugar
1 C. mini marshmallows

Pop popcorn.  In a glass bowl, add remaining ingredients.  Microwave for 2 minutes on high,  Stir briskly.  Microwave for 1 more minute.  Stir until thick and creamy.  Pour over popcorn. 

I've added all the ingredients in separate mini zip locks and then in a clear bag with a bag of popcorn with the instructions as a gift around the holidays.