01 -
Line a 9x13-inch pan with parchment paper and lightly grease the parchment, sides, and spatula with butter or nonstick spray.
02 -
Melt the butter in a large pot over low heat. Add the mini marshmallows and stir until smooth, 4-5 minutes. Remove from the heat.
03 -
Stir in the vanilla, salt, and green food coloring until the marshmallow mixture is evenly colored and bright green.
04 -
Add the crispy rice cereal and fold gently until all the cereal is coated. Work quickly while the mixture is warm and flexible.
05 -
Transfer the mixture to the prepared pan. Press it into an even layer with greased hands or a greased sheet of parchment, using light pressure only.
06 -
Melt the green candy melts with coconut oil in 20-second bursts in the microwave, stirring between each burst, until smooth. Spread in a thin layer over the treats.
07 -
Scatter red heart sprinkles over the wet topping. Let the bars set at room temperature for 30-45 minutes, or chill for 15-20 minutes if you need them faster.
08 -
Lift the slab from the pan using the parchment. Cut into 18 squares with a lightly greased sharp knife.