1. Preheat the oven to 375°F and lightly grease a 9×13-inch baking dish.

2. Bring a large pot of salted water to a boil and cook the lasagna noodles until al dente. Drain and lay them flat so they do not stick together.

3. Heat olive oil in a large skillet over medium heat. Add the onion and cook for 4 minutes, then stir in the garlic for 30 seconds.

4. Add the ground beef and Italian sausage. Cook until browned, breaking the meat into small crumbles. Drain excess grease if needed.

5. Stir in tomato paste, crushed tomatoes, marinara sauce, Italian seasoning, salt, and black pepper. Simmer for 20 minutes, stirring occasionally.

6. In a bowl, mix ricotta cheese, egg, 1/2 cup Parmesan cheese, parsley, and a small pinch of salt and pepper.

7. Spread a thin layer of meat sauce in the bottom of the baking dish. Add a layer of noodles, then meat sauce, ricotta mixture, and mozzarella.

8. Repeat the layers until the ingredients are used, finishing with sauce, mozzarella, and the extra Parmesan on top.

9. Cover loosely with foil and bake for 30 minutes. Remove the foil and bake for 15 to 20 minutes more, until bubbling and golden.

10. Let the lasagna rest for 15 minutes before slicing. Garnish with fresh basil and serve warm.