01 - Preheat the oven to 375°F. Bring a large pot of salted water to a boil. Cook ziti pasta until just al dente, then drain thoroughly.
02 - In a mixing bowl, toss the cooked pasta with crumbled Italian sausage and marinara sauce until evenly coated.
03 - Spread half of the pasta mixture into a baking dish. Dollop ricotta cheese over the layer, then add the remaining pasta mixture on top.
04 - Evenly distribute shredded mozzarella cheese over the surface.
05 - Transfer the dish to the oven and bake for 20 to 25 minutes, or until the cheese is fully melted and the dish is bubbling throughout.