Preheat your smoker to 225°F (107°C).
Cook the elbow macaroni according to package instructions; drain and set aside.
In a large saucepan, melt the butter over medium heat.
Stir in the cream cheese until smooth.
Add milk, sour cream, and smoked paprika; mix well.
Gradually stir in cheddar and mozzarella until melted.
Add the macaroni to the cheese sauce and mix until coated.
Transfer the mixture to a greased baking dish.
Sprinkle breadcrumbs on top if desired.
Smoke for about 30 minutes until bubbly and golden.