In a large pot, melt the butter over medium heat. Add marshmallows, 1 handful at a time. Allow each addition to melt down just a bit to give room for the next handful. Continue stirring to avoid any scorching.
Meanwhile, line a 13 by 9 by 2-inch cake pan/casserole dish with a piece of parchment paper. Allow the excess paper to flap over the side the dish. Spray the parchment lightly with nonstick cooking spray.
Once the marshmallow mixture is gooey enough to stir freely, pour in green food coloring and mix until well blended. Fold in crispy rice. Once the crispy rice is thoroughly incorporated with the melted marshmallow add the cinnamon candy. Remove from heat. Using a rubber spatula, push out the melted mixture into the parchment lined pan.
Spray the remaining piece of 12 by 10-inch parchment paper. Use like a "flat glove" to help mold the crispy treat into the pan. Allow treat to cool about 20 minutes.
Spray the inside of various holiday shaped cookie cutters lightly with nonstick spray. Use your fingers to evenly spread the oil around.
Using the parchment paper lift the entire treat out of the pan, onto a cutting board. Cut holiday shapes out of the rectangular treat.
Meanwhile, melt the white chocolate in a microwave on medium power at 30-second intervals. Make sure to stir in between intervals to avoid scorching. Continue at 30-second intervals, stirring in between until chocolate is smooth and melted.
Drizzle the melted chocolate over the treats and decorate with choice of sprinkles, and remaining cinnamon hard candies.
Stack the treats on a fun platter or cake stand. Or pack in an airtight container and treats will stay fresh for up to 5 days.