Preheat oven to 350°F.
In a skillet, cook ground beef, onion, and garlic over medium heat until beef is no longer pink and onions are soft (about 10 minutes). Drain grease.
Stir in marinara, Parmesan cheese, and Italian seasoning. Simmer for 5 minutes, stirring occasionally. Remove from heat and set aside.
Cook lasagna noodles per package directions. Drain and rinse under cold water. Place on a sprayed sheet pan, lightly coat with cooking spray, and cover with a towel.
In a bowl, mix ricotta, 2 cups mozzarella, ¼ cup Parmesan, egg, and Italian seasoning until well combined.
Spread ½–1 cup sauce on the bottom of a 9x13-inch baking dish.
On a clean surface, spread 3 tablespoons of filling on each noodle. Roll tightly and place seam-side down in the dish. Repeat for all noodles.
Top rolls with remaining sauce. Sprinkle with remaining mozzarella and Parmesan.
Cover with foil and bake for 45 minutes. Uncover and bake an additional 10–15 minutes until cheese is lightly browned.
Garnish with chopped parsley and serve hot.