Preheat your oven to 350°F (175°C).
Prepare the pasta according to package instructions until al dente, then drain and set aside.
In a large mixing bowl, combine the cooked pasta, shredded chicken, marinara sauce, heavy cream, garlic powder, and Italian seasoning.
Season the mixture with salt and pepper to taste, then mix again.
Transfer the pasta mixture to a greased 9x13 inch baking dish, spreading it evenly.
Sprinkle the mozzarella and Parmesan cheeses evenly over the top.
Bake in the preheated oven for 25-30 minutes, or until the cheese is bubbly and golden brown.
Remove from the oven and let it sit for 5-10 minutes before serving.