Creamy Buffalo Chicken Macaroni Bake

Ingredients

• 1 pound elbow macaroni
• 1/2 teaspoon onion powder
• 2 cups shredded rotisserie chicken
• 1/2 teaspoon garlic powder
• 1/2 teaspoon ground black pepper
• 3 tablespoons all-purpose flour
• 1/3 cup ranch dressing
• 2 cups shredded cheddar jack cheese
• 1/2 teaspoon salt
• 1/2 cup buffalo sauce, such as Frank's RedHot
• 3/4 cup panko breadcrumbs
• 5 tablespoons salted butter, divided
• 2 cups whole milk