Preheat oven to 400°F.
To a 13×9 inch baking dish add the pasta, sausage, diced tomatoes with juice, 1 cup of the mozzarella cheese, garlic powder, salt, and black pepper. Stir.
Pour the heavy cream and chicken stock over top and make sure that all of the pasta is submerged
Cover with two layers of aluminum foil and make sure it is very well sealed.*
Put it in the oven until the pasta is tender, about 50 minutes.
Remove from oven and sprinkle with the remaining 1 cup of mozzarella and the Parmesan.
Return to oven uncovered just until cheese has melted, about 5 minutes.
Remove from oven and let the pasta bake rest uncovered for 15 minutes before serving. This is important as the sauce really thickens up in this time.