Preheat oven to 375°F (190°C).
Cook the pasta in salted water until al dente. Drain and set aside.
In a large mixing bowl, combine buffalo sauce, ranch (or blue cheese) dressing, and softened cream cheese. Stir until smooth.
Add the shredded chicken, garlic powder, onion powder, salt, and pepper. Mix well.
Stir in the cooked pasta until evenly coated.
Fold in 1 cup of mozzarella and 1/2 cup of cheddar cheese.
Transfer mixture to a greased 9x13-inch baking dish. Spread evenly.
Top with remaining cheese.
Bake uncovered for 20–25 minutes, or until bubbly and cheese is melted.
Broil for 2–3 minutes at the end for a golden top (optional).
Garnish with green onions or parsley and serve hot.