Prep. Place a piece of parchment paper or a Silpat mat on your work surface. Pour the cereal into a medium bowl and have cones unwrapped and ready to go. Once the cereal treats are made, the faster you work the easier it is so it's important to have everything ready to go.
Make the cereal treats. In a medium saucepan, melt the butter over low heat. Stir in the marshmallows, stirring frequently until completely melted and mixed with the butter. Pour the butter and marshmallow mix into the cereal and stir with a rubber spatula until everything is coated.
Wrap the cones. Using a rubber spatula scoop about ½ cup cereal treats and start wrapping the cereal treats around the first 2 inches of the top of the cone, using the marshmallow to help stick. With a greased hand, lightly press the cereal treats to the cone. Repeat until the top of the cone is completely wrapped.
Let cool. Let the decorated waffle cones sit until cool. Fill with your favorite ice cream and enjoy. To store, wrap each cone in parchment paper then place in an airtight container.
The colder the marshmallow gets, the hard it will be to wrap the cones. So the faster you work the easier it is!
If the cereal treats cool too much, you can pop them in the microwave 10 seconds at a time until warm enough.
Smaller cereal, like Rice Crispies or Fruity Pebbles, is easier to work with than larger pieces, like Reese's Puffs or Lucky Charms.
You can grease your hands with butter or even just wet them with a little bit of water.