Line a cookie sheet with parchment paper. Set aside.

In a microwavable bowl, heat the marshmallows and butter in 30 second intervals, stirring with a spatula in between intervals, until fully melted and smooth. Add about 7-8 drops of green food coloring and mix until the color is well combined. You can add in more food coloring if you’d like a darker green, but not too much, as the marshmallow mixture might water down too much. Add in the Rice Krispies Cereal and the cereal is fully covered.

Spray your hand with cooking spray (or cover with oil/grease) and form 3” x 3” balls with the cereal. Push the ball into your left hand (forming the bottom of the tree) and use the fingers of your right hand to push the mixture up into the shape of a tree. Place on the parchment paper lined cookie sheet, allowing to set for a few hours. Repeat with the remaining mixture, making about 8 trees in total. Spray more cooking spray on your hands as needed.

Once the trees have fully settled (they won’t be soft and warm anymore), make the icing. Using a large spoon, mix together the powdered sugar, milk, and corn syrup in a medium bowl until smooth. Fill a piping bag with the icing, using the Wilton Round #6 tip.

Pipe the icing around the tree to look like a garland, starting at the bottom and ending at the very top. Before the icing drys up, place the M&M;’s about every inch apart along the line of icing. Place one of the gold sugar pearls on top of each tree in replace of a star. Unwrap the peanut butter cups, turn upside down, pipe a medium-sized dot of icing, and place in the middle of the bottom of the trees to look like a tree stump. Allow the icing to set completely. Enjoy!