In a large mixing bowl, whisk together marinara sauce and ricotta until smooth. Add broth (or water) and stir until evenly combined. Gently stir in mozzarella and pasta until all of the pasta is evenly coated in sauce. Pour the mixture into a 13x9 inch baking dish and cover with foil. Refrigerate until ready to bake.
About an hour before baking the pasta, remove the covered dish from the refrigerator and allow it to come to room temperature.
Preheat the oven to 400 degrees F.
Bake the pasta, covered, for 50 minutes. Remove the foil and sprinkle the grated parmesan cheese evenly over the top. Turn on the broiler and return the pan to the oven, broiling until the surface of the pasta is slighly crisp and golden and the parmesan cheese is bubbly, about 5 minutes.
Serve immediately with extra parmesan cheese for sprinkling over the top.