Make Baked Ziti Recipe: a hearty, cheesy casserole with sausage, ricotta, and golden-browned mozzarella.
Preheat the oven to 375°F (190°C), then lightly grease a 9x13-inch (23x33 cm) rectangular baking dish with the room-temperature unsalted butter so the surface is satin and imperceptibly slick. This simple step sets the stage: the butter is just enough to give the final crust a gentle release and a faint golden edge. Keep the prepared pan on the quartz surface, ready and waiting.
Bring a large pot of heavily salted water to a rolling boil and cook the ziti until very al dente—tender at the edges but still firm in the center—then reserve 1/2 cup of the starchy cooking water and drain. Spread the drained ziti out on a shallow metal baking sheet so the tubes cool slightly and do not clump; this keeps the pasta separate and porous so sauce clings to the edges. Set the reserved pasta water in a small glass measure nearby for adjusting sauce viscosity later.

Heat extra-virgin olive oil and sweat the finely chopped onion until translucent with soft golden edges, add garlic for only a few seconds until fragrant, then brown the removed-casing Italian sausage, breaking it into small crumbles. Stir in tomato paste until it darkens and coats the meat, then add crushed tomatoes, water, dried herbs, sugar, salt and pepper and simmer gently until the sauce is slightly reduced, glossy, and richly flavored—thick enough to cling to the pasta but still spoonable. Keep a wooden spoon resting on the pan rim; if the sauce tightens too much, a splash of the reserved pasta water loosens it back to a saucy sheen.

In a medium matte grey ceramic bowl combine whole-milk ricotta, the room-temperature egg, grated Parmesan, chopped parsley, salt and pepper, mixing until completely smooth and uniform with no visible egg streaks. The mixture should be thick, creamy, and spreadable—almost like a dense whipped cream—so it will hold distinct dollops between pasta layers. Rest the spatula in the bowl, showing a glossy ridge of ricotta that captures light.

In a very large mixing bowl gently combine the drained ziti with about three cups of the meat sauce so each tube is evenly coated, then fold in one cup of shredded mozzarella and a quarter-cup of grated Parmesan so there are viscous strings and small pockets of melting cheese throughout. Spread half of this sauced pasta evenly into the buttered rectangular baking dish, dollop the entire ricotta mixture across the surface and gently spread into a rustic even layer, spoon half the remaining meat sauce over the ricotta, sprinkle half the remaining mozzarella and Parmesan, then top with the rest of the sauced pasta and the final layer of sauce and cheeses. If edges look dry, drizzle 2–3 tablespoons of the reserved pasta water around the sides to create steam during baking.

Cover the assembled casserole loosely with foil and bake until the sauce bubbles at the edges, then remove the foil and continue baking until the top is fully melted and golden-browned in spots with glossy, blistered cheese. Let the dish rest for 10–15 minutes to set the layers, then finish with a scattering of finely chopped fresh basil or parsley and a crack of black pepper. Cut into neat rectangular squares and lift out with a wide spatula—each piece should show sealed layers, a moist interior, a golden, slightly crisped cheese crown, and steam that carries the scent of tomatoes, herbs, and browned sausage.
