If you want to make it with unprocessed real cheese the best course of action for extra creamy mac & cheese is to make a Mornay sauce (fancy name for a cheese sauce) and add it to the macaroni before finishing in the oven (or your smoker).
Here's an easy and basic recipe.
Easy Creamy Macaroni and Cheese
6 tbsp butter
6 tbsp all-purpose flour
4 cups whole milk
1 1/2 tsp Colman's dry mustard
Salt
Freshly ground black pepper
1 lb elbow macaroni
3 cups grated cheddar cheese (mild cheddar melts smoothest)
1 1/2 cups freshly grated real parmesan cheese (not the stuff in a plastic jar)
Preheat the oven to 350°F.
Melt the butter in a saucepan over moderately low heat.
Add the flour and cook for 1 to 2 minutes, stirring continuously.
Add the milk in a steady stream, whisking to blend with the butter. Bring the sauce to a boil, still whisking, and add the dry mustard, salt, and pepper to taste.
Reduce heat to medium and slowly add the Cheddar and 1 cup of the Parmesan a little bit at a time while gently whisking constantly.
Continue to cook over low heat until the sauce thickens, about 2 minutes.
Cook the macaroni according to the package instructions.
Drain well, and combine with the sauce.
Transfer the mixture to a buttered shallow baking dish. Sprinkle the remaining Parmesan over the top and bake in the preheated oven for 25 to 30 minutes.
Check for safe temperature.
The top should be browned and bubbling.
Serves 6
HTH
~Martin