Preheat oven to 375°F (190°C). In a large bowl, toss the cubed chicken breasts with olive oil, garlic powder, onion powder, paprika, salt, and black pepper until evenly coated.

Spread the chicken in a single layer on a baking sheet. Bake for 15-20 minutes, or until cooked through and no longer pink.

In a separate bowl, combine the buffalo wing sauce and melted butter. Once chicken is cooked, transfer it to this bowl and toss until thoroughly coated. Set aside.

While the chicken bakes, bring a large pot of salted water to a rolling boil. Add the elbow macaroni and cook according to package directions until al dente (firm to the bite). Drain well and set aside. Do not rinse.

In a large heavy-bottomed saucepan or Dutch oven, melt 1/2 cup butter over medium heat. Whisk in the flour and cook for 1-2 minutes, stirring constantly, to create a roux.

Gradually whisk in the warmed milk and chicken broth until smooth. Continue whisking and cook for 5-7 minutes, or until the sauce has thickened and coats the back of a spoon.

Reduce heat to low. Add the shredded sharp cheddar, Monterey Jack, and cubed cream cheese. Stir constantly until all the cheese is melted and the sauce is smooth.

Stir in the Dijon mustard, optional hot sauce, salt, and black pepper. Taste and adjust seasonings as needed.

Add the drained macaroni to the cheese sauce and stir until evenly coated. Gently fold in the buffalo chicken mixture.

Pour the macaroni and chicken mixture into a greased 9x13 inch baking dish.

For the topping (if using), in a small bowl, combine the panko breadcrumbs and melted butter. Sprinkle evenly over the mac and cheese. If desired, sprinkle with blue cheese crumbles.

Bake for 20-25 minutes, or until bubbly and the topping is golden brown.

Let stand for 5-10 minutes before serving. Garnish with fresh parsley if desired.