Marshmallow Cereal Bars

  Grease 2 (41/2x61/2-inch) rectangular pans; set aside. 

 Melt 3 tablespoons butter in a saucepan over low heat. 

Add 25 large marshmallows and cook until melted, stirring continuously. 

Remove from heat and add 1 1/2 cups cornflakes, 1 cup chocolate cereal, and 1/2 cup chocolate pretzels; mix to combine. 

Press mixture firmly into prepared pans and let cool until set. 

Cut into bars before serving.