Heat a large pot on medium-high heat. Melt butter. Once butter is melted turn off the pot and remove from the heat. Stir in the miniature marshmallows until mostly melted.
Add in the Lucky Charms cereal. Stir until full incorporated.
Spray an 8x8 baking dish with cooking spray. Spread the Lucky Charms mixture into the pan. Patting down with the back of a silicone spatula. Then place the additional marshmallow pieces on top.
Heat the green white chocolate according to package. Drizzle on top of the bars.
Refrigerate for 30 minutes or until firm. Cut into 12 equal peices and enjoy!
Serving: 1g | Calories: 251kcal | Carbohydrates: 47g | Protein: 2g | Fat: 7g | Saturated Fat: 4g | Cholesterol: 14mg | Sodium: 206mg | Potassium: 55mg | Fiber: 1g | Sugar: 29g | Vitamin A: 722IU | Vitamin C: 5mg | Calcium: 96mg | Iron: 5mg