In a large skillet over medium heat, brown Italian sausage and ground beef for about 8-10 minutes. Add chopped onion and minced garlic, sauté for 5 minutes. Stir in crushed tomatoes, tomato paste, and tomato sauce. Season with sugar, basil, fennel seeds, Italian seasoning, salt, and pepper. Simmer uncovered for 1½ hours.

Prepare the cheese mixture in a medium bowl by combining ricotta cheese, large egg, and parsley. Mix thoroughly until smooth.

Preheat your oven to 375°F (190°C). Grease a 9x13-inch casserole dish, spread a thin layer of meat sauce, then layer with oven-ready lasagna noodles. Spread half of the ricotta mixture, followed by mozzarella and more meat sauce. Repeat layers, finishing with noodles, sauce, and topping of mozzarella and parmesan.

Cover the lasagna with greased foil and bake for 25 minutes. Remove the foil and bake for an additional 25 minutes until the cheese is bubbly and golden. Let it rest for 15 minutes before slicing.