Heat the oven to 375°F. Grease 8 cups of a standard muffin pan.

Cook the macaroni according to the package directions until just tender. Drain it, then return it to the pot. Stir in the butter, milk, and cheddar until the cheese melts and coats the pasta. Set aside to cool slightly.

In a large bowl, combine the ground chicken, panko, egg, celery, 2 tablespoons of the buffalo sauce, garlic powder, onion powder, salt, and black pepper. Mix gently until just combined.

Divide about two-thirds of the chicken mixture among the 8 greased muffin cups. Press it across the bottoms and up the sides to make a shallow well in each cup.

Spoon the mac and cheese into the wells, dividing it evenly. Cover each center with the remaining chicken mixture and gently pinch the edges together to seal in the pasta.

Brush the tops with the remaining 2 tablespoons of buffalo sauce. Bake for 22 to 27 minutes, until the chicken is cooked through and the centers reach 165°F.

Let the muffins rest in the pan for 5 minutes before lifting them out. Serve warm so the mac and cheese centers stay creamy.