01 - Preheat your oven to 375°F (190°C). Lightly grease a 9x13-inch baking dish.
02 - Cook the pasta according to the package instructions until it is al dente. Drain thoroughly and set aside.
03 - In a large mixing bowl, vigorously whisk together the buffalo wing sauce, low-fat ranch dressing, and softened cream cheese until the mixture is smooth and well combined.
04 - Add the cooked pasta, prepared chicken, diced celery, and green onions to the bowl with the sauce. Toss gently until all components are evenly coated.
05 - Stir in half of the shredded mozzarella cheese and half of the shredded cheddar cheese into the pasta mixture.
06 - Transfer the combined pasta mixture into the prepared baking dish. Evenly distribute the remaining mozzarella and cheddar cheeses over the top.
07 - Place the dish in the preheated oven and bake for 20 to 25 minutes, or until the cheese is fully melted, bubbly, and shows a light golden hue.
08 - Remove from the oven and allow the bake to cool for 5 minutes before serving. Garnish with fresh parsley and an extra drizzle of buffalo wing sauce, if desired. Serve warm.