Preheat your oven to 375°F. Lightly grease a 9x13 inch baking dish with cooking spray or butter.
Bring a large pot of salted water to a boil. Cook the rotini pasta according to package instructions until al dente. Drain and set aside.
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. Mix well until everything is combined. If the sauce seems thick, add about ½ cup of reserved pasta water.
Pour the mixture into the greased baking dish in an even layer. Sprinkle the remaining mozzarella and Parmesan cheese on top.
Cover with aluminum foil and bake for 20-25 minutes until the cheese is melted and bubbly. For a golden brown top, broil for 2-3 minutes, keeping an eye to avoid burning.
Remove from the oven and let it cool for about 5 minutes. Garnish with chopped fresh parsley if desired. Serve warm and enjoy!
Notes
For extra cheesiness, layer some mozzarella in the middle of the pasta mix.
Adjust the sauce thickness by leaving some pasta water aside.
Prepare it the night before and refrigerate, then bake fresh the next day.