Cook the noodles according to package instructions in salted water until al dente. Drain and transfer to a pot of room temperature water to prevent sticking.

Preheat the oven to 375°F (190°C).

In a Dutch oven, heat the olive oil over medium heat. Add the ground beef and cook, breaking it apart with a wooden spoon, until no longer pink. Drain excess fat if necessary. Season with salt and ground black pepper.

Add the onion and cook for 2 to 3 minutes until translucent. Add the garlic and cook for 30 seconds.

Stir in the marinara sauce, bring to a simmer, and cook for 5 minutes. Remove from heat.

In a medium bowl, combine the ricotta, egg, parmesan cheese, 1 ½ cups of mozzarella, and Italian seasoning. Stir until smooth and well combined.

Spread ½ cup of the meat sauce on the bottom of a 9×13 inch casserole dish.

Lay the noodles flat on a baking sheet. Spread about ¼ cup of the ricotta mixture evenly over each noodle. Top with 1 heaping tablespoon of the meat sauce.

Roll up each noodle and place seam-side down in the casserole dish.

Cover with the remaining meat sauce and top with the remaining 1 cup of mozzarella cheese.

Loosely tent with foil, ensuring the foil does not touch the cheese, and bake for 30 minutes.

Uncover and broil for 1 to 3 minutes, watching carefully, until the cheese begins to brown. Remove from the oven, sprinkle with parsley, and serve.