Start by greasing a 9x13” baking dish with butter to prevent sticking.

In a large, microwave-safe bowl, add mini marshmallows and microwave on high for 20 seconds. Stir the marshmallows and return them to the microwave for another 10-20 seconds until puffed and slightly melted.

In a separate small bowl, measure out salted butter and microwave it in 20-second increments until nearly melted.

Carefully pour the melted butter into the bowl of partially melted marshmallows. Stir until fully incorporated and glossy.

Add a few drops of green gel food coloring to the mixture and stir until evenly distributed.

Gently fold Rice Krispies and Lucky Charms cereal into the colored marshmallow mixture.

Transfer the mixture into the prepared baking dish, using a buttered spatula to evenly spread it across the bottom.

Refrigerate the dish for about 30 minutes or until fully set and cool to the touch.

Once chilled, cut the treats into squares or rectangles and arrange them on a festive plate.