In a large pot, melt the marshmallows and butter over medium-low heat. Be sure to stir them often so that the marshmallows don’t burn.
Once melted, remove the pot from the heat and stir in the Lucky Charms until they’re evenly coated.
Lastly, fold in the sprinkles and then the white chocolate chips just until they’re mixed throughout the cereal.
Press the mixture into a 13 x 9 pan sprayed with baking spray. You can also use parchment paper + cooking spray if you want to be sure they don’t stick. I lightly press down on them with a fondant smoother.
Let the treats cool a bit and then drizzle them with green chocolate and then add sprinkles. Allow them to cool completely and then cut into rectangles.