Let's begin by gathering all the ingredients for this incredible lasagna recipe. In a Dutch oven over medium heat, cook sausage, ground beef, onion, and garlic until beautifully browned. Add crushed tomatoes, tomato sauce, tomato paste, and water to the mixture. Season with sugar, 2 tablespoons of parsley, basil, 1 teaspoon of salt, Italian seasoning, fennel seeds, and pepper. Let the flavors meld together by simmering, covered, for approximately 1 1/2 hours, stirring occasionally.
Meanwhile, bring a generously salted large pot of water to a boil. Cook the lasagna noodles in the boiling water for 8 to 10 minutes. Drain the noodles and rinse them with cold water.
In a mixing bowl, combine ricotta cheese with an egg, the remaining 2 tablespoons of parsley, and 1/2 teaspoon of salt.
Preheat your oven to 375 degrees F (190 degrees C).
Now it's time to assemble the lasagna. Spread 1 1/2 cups of the meat sauce in the bottom of a 9x13-inch baking dish. Arrange 6 noodles lengthwise over the sauce. Spread half of the ricotta cheese mixture on top, followed by one-third of the mozzarella cheese slices. Spoon 1 1/2 cups of meat sauce over the mozzarella and sprinkle it with 1/4 cup of Parmesan cheese.
Repeat these layers and top with the remaining mozzarella and Parmesan cheese. To prevent sticking, either spray the foil with cooking spray or ensure it doesn't touch the cheese. Cover the dish with foil and bake it in the preheated oven for 25 minutes. Then, remove the foil and bake for an additional 25 minutes until it turns golden and bubbly.
Allow the lasagna to rest for 15 minutes before serving. This step ensures the flavors settle and the layers hold together beautifully. Get ready to enjoy a mouthwatering feast that will leave everyone wanting seconds.