Beginning by bringing a large pot of salted water to a rolling boil. Add the lasagna noodles and cook according to package instructions until al dente, about 8-10 minutes. Once cooked, drain and lay the noodles flat on a kitchen towel.

In a large Dutch oven, heat a drizzle of olive oil over medium heat. Add the bulk Italian sausage and ground beef, breaking them apart with a spatula. Sauté for about 5-7 minutes until browned. Toss in the diced onion and continue cooking until translucent. Add minced garlic and sauté for another 1-2 minutes.

Mix in the crushed tomatoes and tomato paste, stirring well. Add a splash of water if the mixture seems too thick. Sprinkle in sugar, fresh parsley, dried basil, fennel seed, salt, and pepper, bringing everything to a gentle simmer. Allow sauce to cook for approximately 30 minutes.

In a medium bowl, combine the egg, ricotta cheese, and a pinch of the remaining parsley and salt. Mix well until smooth and creamy.

In a greased baking dish, start layering with meat sauce. Place three lasagna noodles, half of the ricotta mixture, a layer of shredded mozzarella and grated Parmesan. Repeat this process and finish with a layer of noodles, meat sauce, and a generous topping of cheese.

Cover lasagna tightly with aluminum foil and place in a preheated oven at 375°F (190°C). Bake for 25 minutes, then uncover and bake for another 25 minutes until cheese is bubbling and golden brown. Allow it to cool for about 15 minutes before serving.