Preheat the oven to 350°F (175°C).
Cook the elbow macaroni according to package instructions until al dente. Drain and set aside.
In a large saucepan, melt the butter over medium heat.
Whisk in the flour to form a roux and cook for 1-2 minutes, stirring constantly until lightly golden.
Gradually whisk in the whole milk and heavy cream, continuing to whisk until the mixture thickens and is smooth, about 5 minutes.
Remove the sauce from heat and stir in 2 1/2 cups of shredded cheddar cheese until melted and smooth.
Season the cheese sauce with salt, black pepper, garlic powder, onion powder, and smoked paprika.
Add the cooked macaroni and shredded chicken to the cheese sauce and stir until fully combined.
Transfer the mac and cheese mixture to a greased 9×13 inch baking dish.
In a small bowl, combine the panko breadcrumbs, grated Parmesan cheese, and remaining 1/2 cup shredded cheddar cheese.
Sprinkle the breadcrumb mixture evenly over the top of the casserole.
Bake in the preheated oven for 25-30 minutes, or until the top is golden brown and the casserole is bubbly.
Remove from the oven and let it rest for 5 minutes before serving.