Add marshmallows and stir until completely melted. Remove from heat.
Add rice krispies and stir until well blended.
Butter a 9x13 pyrex dish.
Press mixture evenly into the dish, and cover with saran wrap.
Refrigerate overnight.
Cut into squares when cool.
Serve and enjoy!
Notes
This is a classic favorite dessert and one of only a few desserts my mother included in the cookbook she made for me when I graduated from college. It's great to keep these ingredients on hand so you can make it whenever you're moved by the spirit!