Melt butter over medium heat. Add in marshmallows and mix until thoroughly combined and marshmallows are almost fully melted. Add in sugar cookie mix and mix until well combined.
Turn off heat and add in Rice Krispies. Mix well!
Add in mini marshmallows and Christmas sprinkles.
Transfer to a well-greased Pyrex. Press into the Pyrex to mold the treats! Add more sprinkles!
Let cool before cutting. Enjoy!
