Bring a large pot of salted water to a boil. Add the elbow macaroni and cook until al dente according to package directions. Drain and set aside.

In the same pot (or a large skillet), melt the butter over medium heat. Add the flour and whisk continuously for about 1 minute until it becomes a golden paste. Slowly pour in the milk, whisking constantly to prevent lumps. Continue to cook until the sauce thickens, about 3 to 4 minutes.

Reduce the heat to low. Add the shredded cheddar, smoked cheddar, and cream cheese. Stir until completely melted and smooth. Season with garlic powder, onion powder, smoked paprika, salt, and pepper. Taste and adjust.

In a small bowl, toss the shredded chicken with the BBQ sauce until well coated.

Add the cooked pasta and the BBQ chicken to the cheese sauce. Stir gently until everything is evenly coated. If the mixture seems too thick, add a splash of milk to loosen it.

Optional: If you like a crunchy contrast, transfer the mac and cheese to an oven safe baking dish. Sprinkle with panko breadcrumbs mixed with a little melted butter. Broil for 2 to 3 minutes until golden and bubbly.

Garnish with chopped green onions or fresh parsley. Serve immediately.