Butter an 8 x 8-inch or 9 x 9-inch baking dish. Set aside.
Heat a large saucepan over low heat. Add 4 ½ cups of marshmallows and the butter. Stir until melted.
4 tablespoons unsalted butter
Pour in the cereal, and stir until well combined. Remove from heat and add the remaining 1 cup of marshmallows.
6 cups Fruity Pebbles Cereal
Transfer the mixture to the prepared baking dish, and use a buttered spatula or buttered hands to press the mixture into an even layer.
Allow the bars to set for at least 30 minutes before slicing and serving.
See post for tips and storage options.
Notes
*The calories listed are an approximation based on the ingredients in the recipe card and a serving size of 1 marshmallow treat. Actual calories will vary.*For more information, tips, and answers to frequently asked questions, please refer to the post.