Heat a 12" cast iron skillet over medium heat.
Add the butter and let melt. Whisk in the flour until smooth and slightly thickened.
Whisk in the garlic powder and mustard powder.
Whisk in the milk, heavy cream and hot sauce (if using) and bring to a gentle boil, while whisking. Reduce the heat.
Whisk in the cream cheese, until fully melted.
Whisk in the shredded cheese and stir until melted. Turn off the heat and add in the cooked macaroni noodles. Stir until the noodles are fully coated in cheese sauce.
Transfer the skillet to the smoker, close the lid, and smoke for a minimum of 1 hour and a max of 2 hours.
Serve immediately for best texture.