Prepare the Lasagna Sauce: In a large skillet over medium-high heat, brown the ground beef and Italian sausage with the diced onion for 5-7 minutes. Add minced garlic and cook for 1 more minute.
Pour in the red wine (or broth) and stir until almost evaporated (about 2 minutes).
Add marinara sauce, tomato paste, Italian seasoning, sugar, salt, pepper, and parsley. Bring to a simmer, cover, and cook for 5-10 minutes to meld flavors.
Make the Cheese Filling: In a large bowl, combine ricotta, cottage cheese, 1 cup of mozzarella, the egg, parsley, and Parmesan cheese. Mix until thoroughly combined.
Cook the Noodles: Bring a large pot of salted water to a boil. Cook noodles until al dente (8-10 mins). Drain and rinse under cold water to prevent sticking.
Preheat Oven: Preheat your oven to 375°F (190°C).
Layer the Lasagna (Bottom): Spread 1 cup of meat sauce in the bottom of a 9x13-inch baking dish.
First Layer: Add 3-4 lasagna noodles. Spread with ⅓ of the cheese mixture, sprinkle with 1 cup of mozzarella, and top with 1 cup of meat sauce.
Second Layer: Repeat: Noodles, ⅓ cheese mixture, 1 cup mozzarella, 1 cup meat sauce.
Final Layers: Add the last noodles. Top with all remaining meat sauce, then sprinkle with the last 1 cup of mozzarella and extra Parmesan.
Bake: Cover with foil and bake for 25 minutes. Remove foil and bake for 20-25 more minutes until bubbly and golden.
Rest: Let the lasagna rest for 15-20 minutes before slicing and serving.