Line a 9×13-inch pan with parchment paper, leaving a little overhang, and lightly grease it to prevent sticking.

Measure out the Rice Krispies and Lucky Charms. From the Lucky Charms, set aside about ½ cup of the marshmallows for topping later.

In a large pot over low heat, melt the butter. Add the marshmallows and stir constantly until the mixture is smooth and fully melted.

Remove from heat and quickly stir in the Rice Krispies, followed by the Lucky Charms, until everything is evenly coated.

Transfer the mixture to the prepared pan. Use a lightly greased spatula or wax paper to press it evenly into the pan without packing it down too tightly.

Place the chocolate in a microwave-safe bowl. Microwave in 30-second intervals, stirring well after each, until completely melted and smooth.

Drizzle the melted chocolate over the cereal mixture, then sprinkle the reserved Lucky Charms marshmallows evenly on top.

Let the treats set at room temperature for about 1 hour. Once firm, cut into squares (6 rows by 4 rows works well).

Serve and enjoy!