Heat olive oil in Dutch oven over medium heat. Cook onion until translucent, 5-7 minutes.
Add sausage, break apart, and brown completely.
Add wine, deglaze pot, reduce by half.
Stir in tomato paste, crushed tomatoes, oregano, red pepper flakes, salt and pepper. Simmer partially covered 30 minutes.
Preheat oven to 375F.
Cook ziti 2-3 minutes less than package directions.
Mix ricotta, 3/4 of mozzarella, Parmesan, egg, and basil in bowl.
Combine cooked pasta with sauce.
Layer half pasta mixture in 9x13 baking dish.
Spread ricotta mixture over pasta.
Top with remaining pasta and sauce.
Sprinkle with remaining mozzarella and extra Parmesan.
Bake uncovered 25-30 minutes until bubbly and cheese browns.
Rest 10 minutes before serving.
Note: Pasta must be very al dente as it will continue cooking in oven.