Preheat oven to 375°F. Grease a 9x13 or similar casserole dish.
In a large skillet on medium high heat, add ground beef and onion. Cook until meat is browned, breaking up with meat chopper (or wooden spoon), about 5-7 minutes.
Add pasta sauce, diced tomatoes, water, Italian seasoning, salt, and pepper mix. Bring to a boil, reduce heat, and simmer for 10-15 minutes or until thickened.
Meanwhile, in a large pot of salted water, cook rigatoni per package directions until al dente. Drain.
In a medium bowl, combine ricotta, herbs, egg, 1 cup mozzarella cheese, and parmesan.
Add about 1 cup of sauce to the bottom of the dish. Add half of the rigatoni. Spoon about half of the sauce over top. Spoon the ricotta overtop, spreading lightly.
Add remaining rigatoni, and spoon with remaining sauce. Sprinkle with remaining 1 cup mozzarella cheese.
Bake 25-30 minutes or until golden and bubbly.
Notes
Cook pasta al dente and reserve ½ cup of pasta water in case you need to thicken the sauce.
Keep leftover baked rigatoni covered in the refrigerator for up to 3 days.
Freeze baked rigatoni pasta by covering it in plastic wrap, then cover it in foil and freeze for up to 3 months.