In a large skillet over medium heat, warm olive oil and sauté onion until translucent. Add garlic and cook 1 minute more.

Add sausage and ground beef, breaking into crumbles. Cook until browned, about 8 minutes. Drain excess fat.

Stir in crushed tomatoes, tomato paste, basil, oregano, salt, and pepper. Simmer uncovered for 30 minutes, stirring occasionally.

Meanwhile, preheat oven to 375°F (190°C). In a bowl, mix ricotta cheese with egg, half the Parmesan, and a pinch of salt.

Spread a thin layer of meat sauce in a 9×13-inch baking dish. Layer 4 noodles, half the ricotta mixture, one-third of mozzarella, and one-third of sauce. Repeat layers once more.

Top with remaining noodles, sauce, mozzarella, and Parmesan. Cover with foil (sprayed with cooking spray to prevent sticking).

Bake for 25 minutes covered, then remove foil and bake 20 more minutes until bubbly and golden.

Let rest 15 minutes before slicing. Garnish with fresh basil leaves.