Spray a 9x13 baking dish with non-stick cooking spray; set aside.
Place chips in freezer while you prepare the other ingredients.
In a large bowl, add the cereal and set aside.
Add butter to a sauce pan and melt over medium high heat. Once butter is melted add in 5 cups of the mini marshmallows, stirring until mostly melted. Remove from heat and stir in vanilla.
Add melted butter mixture to the large bowl with cereal. Stir to coat entire bowl of cereal.
Add the cold chocolate chips and remaining cup of marshmallow. Stir until everything is mixed well.
Transfer mixture to prepared baking dish and smooth into an even layer. Cover and refrigerate until set.
Cut into squares and keep stored in an air tight container.