01 - Preheat oven to 375°F. Grease a 9x13-inch baking dish with cooking spray or butter.
02 - Boil pasta in a large pot of salted water until al dente, about 2 minutes less than package directions. Drain thoroughly.
03 - In a large skillet over medium heat, combine heavy cream, pesto, chicken broth, garlic, salt, and pepper. Simmer for 2–3 minutes, stirring occasionally.
04 - Stir in Parmesan cheese until completely melted and sauce is smooth and creamy.
05 - Add cooked pasta, chicken, cherry tomatoes, and spinach to the skillet. Toss everything together until evenly coated with sauce.
06 - Transfer the mixture to the prepared baking dish. Sprinkle mozzarella cheese and additional Parmesan evenly over the top.
07 - Bake for 20–25 minutes, or until cheese is melted and golden brown with bubbling edges.
08 - Let the dish rest for 5 minutes before serving. Garnish with fresh basil leaves if desired.