Preheat the oven to 375F.
In a large pot, bring water to a boil. Add pasta and salt. Cook for 8-10 minutes. Pasta shouldn't be completely cooked (it will continue cooking in the oven). Drain and rinse with cold water. Set aside.
Add ricotta cheese, crushed tomatoes, 1 ½ cups shredded mozzarella cheese, beaten egg, red pepper flakes, dried oregano, salt, and pepper, to a large bowl. Then, add ziti and mix until combined.
Grease a 9x13 inches baking dish with non-stick cooking spray. Then, add 1 cup tomato sauce and spread evenly. Transfer cheesy ziti mixture to the baking dish. Spread evenly. Then, pour the remaining 1 cup of tomato sauce over the ziti layer. Sprinkle with the remaining ½ cup shredded mozzarella cheese and parmesan cheese. Bake in the preheated oven for 20-25 minutes or until completely heated, browned and cheese melted. Enjoy!