Step 1: Prepare the Meat Sauce

1. In a large skillet or saucepan over medium heat, cook the ground beef until browned. Break it apart with a spoon while cooking. Drain excess fat if necessary.

2. Add the chopped onion and minced garlic to the pan, sautéing for 2-3 minutes until fragrant.

3. Stir in the crushed tomatoes, tomato sauce, tomato paste, and water. Mix well to combine.

4. Season with basil, oregano, salt, pepper, sugar, and red pepper flakes. Let the sauce simmer uncovered for at least 30 minutes, stirring occasionally. The longer it simmers, the deeper the flavor.

Step 2: Prepare the Ricotta Mixture

1. In a medium bowl, combine the ricotta cheese, egg, Parmesan cheese, parsley, salt, and black pepper. Stir until smooth and well incorporated. Set aside.

Step 3: Cook the Lasagna Noodles

1. Bring a large pot of salted water to a boil and cook the lasagna noodles according to the package instructions. If using no-boil noodles, skip this step.

2. Drain the noodles and lay them flat on a baking sheet to prevent sticking.

Step 4: Assemble the Lasagna

1. Preheat the oven to 375°F (190°C).

2. Spread 1 cup of the meat sauce evenly on the bottom of a 9×13-inch baking dish.

3. Arrange 3-4 lasagna noodles on top of the sauce, slightly overlapping.

4. Spread 1/3 of the ricotta mixture over the noodles, followed by 1 cup of meat sauce and a sprinkle of mozzarella cheese.

5. Repeat the layers (noodles, ricotta, sauce, mozzarella) until all ingredients are used, ending with a generous layer of mozzarella and Parmesan on top.

Step 5: Bake the Lasagna

1. Cover the dish with aluminum foil and bake for 25 minutes.

2. Remove the foil and bake for an additional 20-25 minutes, or until the cheese is melted and bubbly.

3. Let the lasagna rest for 10-15 minutes before slicing to allow the layers to set.