Preheat your oven to 375°F (190°C) and lightly grease a 9x13 inch baking dish.
Cook the ziti in salted water until just shy of al dente – about 2 minutes less than package instructions. The pasta will continue cooking in the oven.
While the pasta cooks, brown the Italian sausage in a large skillet over medium heat, breaking it into smaller pieces.
Add minced garlic to the sausage and cook for another minute until fragrant.
In a large bowl, combine ricotta, eggs, 1 cup mozzarella, 1/4 cup Parmesan, basil, and oregano.
Drain the pasta and return it to the pot. Add the marinara sauce and sausage mixture, stirring to combine.
Layer half the pasta mixture in the baking dish, spread the ricotta mixture evenly on top, then add the remaining pasta.
Top with remaining mozzarella and Parmesan cheese.
Cover with foil and bake for 25 minutes, then remove foil and bake for another 10-15 minutes until cheese is golden and bubbly.