1️⃣ Preheat Oven: Preheat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish with cooking spray or butter.

2️⃣ Prepare the Pasta Mixture: In a large mixing bowl, combine the cooked rotini pasta, diced or shredded chicken, Alfredo sauce, garlic parmesan sauce, half of the shredded mozzarella cheese, and half of the grated Parmesan cheese. Season with salt and pepper to taste. Add about 1/2 cup of the reserved pasta water if you prefer a saucier texture.

3️⃣ Assemble the Casserole: Transfer the pasta mixture to the prepared baking dish, spreading it evenly. Sprinkle the remaining mozzarella and Parmesan cheese over the top for a melty, cheesy crust.

4️⃣ Bake: Cover the baking dish with aluminum foil and bake for 20-25 minutes, or until the cheese is melted and the casserole is bubbly.

5️⃣ Optional Broil: For a golden top, remove the foil and broil on high for 2-3 minutes, watching carefully to avoid burning.

6️⃣ Garnish and Serve: Allow the casserole to cool for about 5 minutes. Garnish with chopped fresh parsley if desired and serve warm. Enjoy this creamy, cheesy pasta dish!