In a microwave-safe bowl, add butter and Campfire Mini White Marshmallows. Heat in the microwave for 3 minutes, stirring halfway through.
Divide Rice Krispie cereal among two mixing bowls. Add half of the marshmallow mixture to one and stir until well combined. Stir in pink food coloring to the remaining marshmallow mixture until no streaks remain. Add mixture to the other bowl of Rice Krispies and stir until well combined.
Dump each mixture into the prepared pans and flatten. Add sprinkles to the plain Rice Krispies. Cover both pans then transfer to the fridge to set for at least 30 minutes.
Use a heart-shaped cookie cutter to cut out shapes. Add melted red candy melts to a piping bag and decorate with “xoxo” if desired.
Transfer hearts to a platter to serve - they are best the day of.