Quickly add the crispy rice cereal and some sprinkles, chocolate chips, and/or green food coloring (if using). Make sure to stir well so the cereal is coated with the melted marshmallow mixture.
Remove the molded Rice Krispie Treat from the shell, gently place it on a plate, and allow it to set.
Once set, place it inside one of the avocado shells and cover it with the other.