Bring a large pot of salted water to a boil. Add 8 ounces of rotini pasta and cook according to package instructions until al dente. Drain well and set aside.
In a large mixing bowl, combine 2 cups shredded cooked chicken with 1 cup buffalo sauce, 1/2 cup softened cream cheese, 1/2 cup ranch dressing, 1 cup shredded cheddar cheese, 1 teaspoon garlic powder, 1 teaspoon onion powder, and salt and pepper to taste. Mix until creamy and well incorporated.
Add the cooked rotini pasta and 1 cup chopped green onions to the bowl with the chicken mixture. Stir gently until the pasta is evenly coated with the sauce.
Spray a 9x13-inch baking dish with non-stick spray or lightly grease it. Pour the pasta and chicken mixture into the dish, spreading it out evenly. Sprinkle 1/2 cup crumbled turkey bacon over the top, followed by 1/2 cup additional shredded cheddar cheese.
Preheat your oven to 350°F (175°C). Bake the casserole uncovered for 20-25 minutes, or until the cheese on top is melted and bubbly with golden spots.
Remove from the oven and let it cool for a few minutes. Garnish with extra chopped green onions if desired. Serve warm and enjoy!