Preheat oven to 350 degrees.
Line a 12 cup cupcake pan with liners.
Prepare the cake mix according to directions. Add green food coloring and mix until the batter is completely green. Pour into the cupcake pan.
Bake for 15 minutes.
Let cool.
Frost the top of the cupcakes with this Betty Crocker Cupcake Frosting or use regular white frosting.
On a piece of parchment paper, lay down 12 Oreo cookies. Spray them with the Wilton Food Spray - make sure to cover both sides and let dry.
Place each Oreo on top of each cupcake to represent a gold coin. Place Lucky Charms marshmallows on top of the rest of the frosting.