Start by lignin a 9x13 inch pan with parchment paper and grease lightly.
Melt the butter over medium heat in a large pot. Stir until completely melted.
Remove from heat and then stir in Rice Krispies and the Lucky Charms until coated.
Press the mixture into your pan.
Melt the white chocolate melts in 30-second microwave intervals, stirring between each until completely melted .
Drizzle the white chocolate over the Rice Krispies and top with the reserved marshmallows. If desired can add some green sprinkles for a bit more color, too.
Let it set for about one hour, until set, then cut into squares of size of choice.
