Melt the butter in a large pot over low heat. Add the mini marshmallows and stir until completely melted and smooth. Remove from the heat and immediately stir in the Rice Krispies cereal until evenly coated.

Press the mixture into a parchment-lined or lightly greased 9x13-inch baking pan, spreading it into an even layer.

Refrigerate for at least 1 hour, or until fully set.

Lift the treats from the pan using the parchment paper and transfer to a cutting board. Cut into squares or rectangles.

Melt the red, white, and blue candy melts according to the package directions, using bowls deep enough for dipping if desired.

Dip each Rice Krispie treat into the melted candy coating, or use a spoon to drizzle the candy over the tops to create a festive red, white, and blue design.

Place the treats on parchment paper and immediately add sprinkles while the candy coating is still wet.

Let the coating set completely at room temperature or refrigerate briefly to speed up the process.