In a large saucepan, melt the butter over low heat. Add the mini marshmallows and stir until completely melted and smooth.

Stir in a few drops of green food coloring until the mixture reaches your desired shade of Christmas green.

Remove from heat and quickly stir in the Rice Krispies cereal until evenly coated.

Working with buttered hands, scoop a small handful of mixture and form into cone shapes to resemble Christmas trees. Place them on a parchment-lined baking sheet.

While still slightly sticky, roll each tree in green decorating sugar to give it a sparkling, festive look. Sprinkle nonpareils or holiday sprinkles around the tree to look like ornaments.

Place a small yellow candy star on top of each tree for the perfect finishing touch.

Allow the trees to cool and set completely before serving.