Bring a large pot of salted water to a boil. Add the elbow macaroni and cook until al dente according to package directions, about 7 to 8 minutes. Drain and set aside.

In a large skillet over medium heat, melt 2 tablespoons of butter. Add the cubed chicken, season with salt, pepper, and garlic powder, and cook for 5 to 7 minutes until golden and cooked through (internal temperature of 165 degrees F). Transfer to a plate.

In the same skillet, melt the remaining 2 tablespoons of butter over medium-low heat. Whisk in the flour and stir for about 1 minute until it smells slightly nutty.

Slowly pour in the milk while whisking constantly. Continue whisking for 4 to 5 minutes until the sauce thickens and coats the back of a spoon.

Reduce heat to low. Add the shredded cheddar gradually, a handful at a time, stirring until fully melted and smooth. Season with salt and pepper to taste.

Fold in the cooked pasta and chicken until evenly coated in the cheese sauce.

Optional baked version: Transfer the mixture to a greased oven-safe dish. Top with breadcrumbs and bake at 350 degrees F for 20 minutes until golden and bubbling.

Serve warm, garnished with fresh parsley.