Cook the pasta in a large pot in accordance with the instructions on the package, then drain and rinse.
Heat butter until melted, then add flour and whisk.
Add the milk and heavy whipping cream and stir, then add half of the cheese and onion powder, smoked paprika, salt, and pepper.
Return the pasta to the large pot. Drizzle the cheese sauce over the pasta and stir until fully combined.
Begin to layer the pasta into a 12 inch cast iron skillet.
Add a layer of cheese, then another layer of pasta, and a final layer of cheese.
Smoke for 1-2 hours until the cheese on top has melted.