Preheat Oven: Preheat oven to 375°F (190°C). Grease a 9×13-inch baking dish and set aside.

Cook Pasta: Bring a large pot of salted water to a boil. Add ziti and cook until al dente, according to package instructions. Drain and set aside.

Prepare Sausage Sauce:

• Heat olive oil in a large skillet over medium heat.

• Add sausage and cook until browned. Break it apart with a spoon.

• Add onions and garlic; sauté until softened.

• Pour in marinara sauce, oregano, and basil. Simmer for 10 minutes. Adjust seasoning with salt and pepper.

Prepare Ricotta Mixture:

• In a medium bowl, combine ricotta cheese, egg, Parmesan cheese, and a pinch of salt and pepper. Mix until smooth.

Assemble the Ziti:

• Spread a thin layer of sauce at the bottom of the baking dish.

• Layer half of the cooked ziti over the sauce.

• Spoon half of the ricotta mixture over the ziti.

• Spread half of the sauce over the ricotta mixture.

• Sprinkle 1 cup of mozzarella cheese.

• Repeat the layers: ziti, ricotta mixture, sauce, and top with remaining mozzarella cheese.

Bake: Cover with foil and bake for 20 minutes. Remove foil and bake for an additional 10-15 minutes, or until cheese is golden and bubbly.

Garnish and Serve: Let the baked ziti rest for 10 minutes before slicing. Garnish with fresh parsley and serve warm.