Prepare the Base Treat Melt the butter in a large pot over low heat. Add the mini marshmallows, stirring until the mixture is smooth and completely melted. Remove the pot from heat and immediately mix the Rice Krispies cereal until well coated. Press the mixture firmly into a 9x13-inch baking pan lined with parchment paper or lightly greased. Flatten it evenly across the pan. Let the Rice Krispie treat cool and set in the refrigerator for at least one hour.

Cut the Treats Once set, lift the whole treat out of the pan using the edges of the parchment paper. Place it on a cutting board and cut it into squares or rectangles to your preferred size.

Melt the Candies Melt the red, white, and blue meltable candies separately according to the package instructions. Use bowls deep enough for easy dipping.

Drizzle the Treats Dip each Rice Krispie square into your chosen melted candy, covering it to your liking. Let any excess drip off. Place the dipped treats onto a sheet of parchment paper. While the candy coating is still wet, sprinkle with your chosen sprinkles for a decorative touch.

Cool the Rice Krispie Treats Allow the treats to set completely at room temperature or in the refrigerator for a faster setting.