Prepare a 9x13 baking dish by spraying with nonstick spray. Set aside.
Melt 3 tablespoons of butter in a large pot over medium heat
Add 5 cups of mini marshmallows to the pot and stir to coat in the butter. Continue to stir until the marshmallows have melted completely.
Turn off the heat. Add 6 cups of rice krispie cereal and stir in quickly. As the marshmallows cool, the mixture will firm up.
Dump all of the marshmallow and cereal mixture into the baking dish. Press down with spatula and spread out evenly. Use a large piece of plastic wrap to cover the rice crispie treats and press into the baking dish to create a uniform thickness. Allow to set for 30 minutes or more.
After the rice krispie treats have set, run a butter knife along the edges to loosen it from the baking dish.
Use cookie cutters to cut out desired shapes such as Christmas trees, snowman, snow globe, and a Christmas ornamnet.
Melt chocolates in a microwave safe dish and pour into disposable piping bags. Cut off the tip and get to decorating. Be creative and most of all, have fun!
After the chocolae sets, they are ready to enjoy!