In a large pot, cook the tortellini according to the package instructions until they are perfectly al dente. Once cooked, drain the tortellini and set them aside to cool briefly.
In a spacious mixing bowl, combine the drained tortellini with the Alfredo sauce. If using, add the diced, cooked chicken as well. Fold in the chopped spinach, garlic powder, Italian seasoning, and a generous pinch of salt and pepper. Mix thoroughly until everything is evenly coated in the creamy sauce.
Grease a 9x13 inch baking dish with cooking spray or butter, then carefully transfer the tortellini mixture into the dish, spreading it out evenly for consistent baking.
Generously sprinkle the shredded mozzarella cheese over the top of the tortellini mixture. Follow with a light dusting of grated Parmesan cheese.
Cover the baking dish with aluminum foil to prevent the cheese from burning. Place it in the preheated oven and bake for 20 minutes.
After 20 minutes, carefully remove the foil and continue baking for an additional 10-15 minutes until the cheese becomes bubbly and golden brown.
Once out of the oven, allow the dish to cool for about 5 minutes.
Just before serving, garnish with freshly chopped parsley.
Notes
Serve with a light salad for a refreshing contrast.