Preheat oven to 350°.
Boil ziti per the package direction until it's al dente.
While the ziti is boiling, brown the Italian sausage.
Pour off any excess liquid.
Mix ricotta, 3/4 cup of mozzarella cheese, egg, and parmesan cheese, and set aside.
In a large bowl combine cooked ziti and cooked sausage.
Top with ricotta mixture and stir until completely incorporated. Careful not to break the ziti noodles.
Add pasta sauce, Italian seasoning, and red pepper flakes and mix.
Spray a casserole dish with non-stick cooking spray.
Transfer ziti mixture to the casserole dish, cover with aluminum foil, and bake for 25 minutes.
Remove foil, top with remaining 1/4 cup mozzarella cheese and bake, uncovered, for 10 more minutes.
Garnish with fresh basil.
Serve with garlic bread and a side salad.