Preheat your smoker to 250°F.
Chop the Velveeta, Gouda, and 8oz of the sharp cheddar cheese into cubes.
Add the cubed Velveeta, Gouda, and sharp cheddar cheese to a 9x12 baking dish. Place the block of cream cheese on top.
Sprinkle the garlic powder, onion powder, smoked paprika, chili powder, salt, and pepper over the top of the cheese. Pour the milk over the top of everything.
Place on the grates of the smoker for one hour.
In the meantime, shred the remaining 8oz of cheddar cheese and boil the macaroni until al dente (about 10 minutes).
After one hour, stir the cheese mixture until well combined and creamy. If the mixture looks too thick, add more milk as needed.
Pour the al dente macaroni into a large bowl and add the cheese mixture. Give it a good mix until all the noodles are coated in the cheese sauce.
Transfer the macaroni and cheese to the same baking dish, then top with the remaining shredded cheddar cheese and place back on the smoker, increasing the temperature to 325°F.
Let it smoke for another 30 minutes or until the cheese is golden brown and melted on top. Serve immediately and enjoy!