Preheat the oven to 375°F (190°C) and grease a 9x13-inch baking dish.
Cook the penne pasta according to the package instructions until al dente, then drain and set aside.
In a large skillet over medium heat, melt the butter, then add the heavy cream and ranch seasoning mix. Whisk until well combined and slightly thickened, about 3-4 minutes.
Stir in the cooked chicken, crumbled turkey bacon, and half of both cheeses into the sauce. Mix until the cheese is melted and the mixture is creamy.
Combine the cooked pasta with the creamy chicken ranch mixture and season with salt and black pepper to taste. Transfer the mixture into the prepared baking dish.
Sprinkle the remaining mozzarella and cheddar cheese on top. Bake for 20-25 minutes, or until the cheese is bubbly and golden. Garnish with chopped parsley before serving, if desired.