Shred all the cheeses and reserve a 1/2 cup of the smoked cheddar. Cut the Velveeta into 1 inch cubes.
Bring a large pot of salted water to a boil. Cook the macaroni until al dente per the package instructions. Drain.
While boiling the macaroni, in a small sauce pan, combine cream, milk and butter over medium-low heat and warm until butter is melted.
Add mustard powder, nutmeg, pepper, salt, and diced chiles and stir until combined.
Preheat the smoker or oven to 350 degrees.
Add all the cheeses (except 1/2 cup of Smoked Cheddar reserved for topping) to the cooked pasta and pour sauce over the cheese and pasta. Stir until just combined.
Spray a 9 x 13 pan with cooking spray and pour the pasta into it. Top with 1/2 cup reserved smoked cheddar.
Bake until the cheddar is melted, about 25 minutes. Consider covering with foil half way through if using a smoker, to avoid it being overly smoky.