In a large saucepan, melt the butter over low heat. Add the mini marshmallows and stir until completely melted and smooth. Remove from heat and stir in the vanilla extract.
Add the crispy rice cereal to the marshmallow mixture and stir until well coated.
Allow the mixture to cool slightly, then press it firmly into a greased 9x13-inch baking dish. Let it cool completely for about 30 minutes.
Once cooled, cut the marshmallow treat into squares or rectangles. Insert a lollipop stick into each piece.
Melt the red, white, and blue candy melts separately according to package instructions.
Dip each marshmallow treat pop into the melted candy melts, allowing any excess to drip off. Immediately sprinkle with red, white, and blue sprinkles while the coating is still wet.
Place the decorated pops upright in a cup or stand to allow the coating to set completely.