Preheat oven to 400 degrees and grease a 9x13 inch pan.
In a large bowl, stir together the cooked ziti, sausage, and all but 1 cup of marinara sauce. Spread half of the ziti mixture in the bottom of your prepared pan.
Spoon half of the ricotta and mozzarella evenly over the top. Top with the rest of the ziti mixture, then remaining ricotta, mozzarella, and reserved marinara sauce.
Bake 20-25 minutes, until the sauce is bubbling and cheese is melted. Sprinkle the basil and parsley over the ziti and serve warm.