1. Preheat the oven to 425°F. Set aside 1 cup of mozzarella for topping.
2. Cheese Mixture: In a bowl, mix remaining mozzarella, ricotta, cottage cheese, parmesan, eggs, parsley, and pepper.
3. Sauce: In a large skillet, brown ground beef, onion, and garlic over medium-high heat. Drain excess fat, stir in marinara sauce, and simmer for 5 minutes.
4. Noodles: If using traditional gluten-free noodles, parboil according to package instructions, then lay them on a sheet to prevent sticking. Otherwise, prepare oven-ready noodles.
5. Assemble in a 9×13 baking dish: Spoon a thin layer of sauce at the bottom. Layer 3 noodles. Add half the cheese mixture, spreading evenly. Add a layer of meat sauce. Repeat layers ending with noodles and remaining sauce. Top with reserved mozzarella.
6. Bake: Cover with foil, bake for 40 minutes. Uncover and bake an additional 20 minutes until cheese is browned and bubbly.
7. Rest: Let sit 15-20 minutes before slicing and serving.