Preheat the oven to 375° Fahrenheit. Cook the pasta according to the package instructions.
Combine penne pasta, rotisserie chicken, and chopped bacon with the Alfredo sauce and the Ranch dressing in a large bowl. Make sure everything is well coated.
Spray a baking dish with cooking spray. Transfer the mixture to a large oven-proof casserole dish. Top with grated Mozzarella and Cheddar Cheese.
Cook the Chicken Bacon Ranch Casserole in the oven for 20-25 minutes or until you see an evenly baked golden crust. Remove from the oven and serve immediately.