Set a pan to medium heat and add the butter. Once the butter has melted, add the marshmallows and mix until fully melted. Remove from the heat and add the Lucky Charms cereal. Mix until fully combined.

Spray a cookie sheet with cooking spray and turn the cereal out onto the sheet. Use a rubber spatula to flatten out the cereal as much as possible. Allow to cool completely.

Slice the Lucky Charms into triangles with a sharp knife. Spray your hands with cooking spray and shape the triangles into cones.

Place the cones on a plate lined with wax paper and freeze until stiff, about 10-20 minutes. Then fill with ice cream and enjoy!