In a large skillet, cook the ground beef and diced onion over medium heat until browned. Add the minced garlic and cook for an additional minute, stirring to combine. Drain any excess fat from the pan.

Stir in the crushed tomatoes, tomato sauce, Italian seasoning, and salt. Allow the mixture to simmer for 10–15 minutes.

In a separate bowl, mix together the ricotta cheese, large egg, and optional chopped parsley until smooth.

In a 9×13 baking dish, spread a thin layer of the prepared meat sauce. Place 3 oven-ready lasagna noodles on top, followed by meat sauce, the ricotta mixture, and a sprinkle of mozzarella. Repeat the layers two more times.

Finish with the remaining meat sauce and generously top with mozzarella and grated Parmesan cheese. Cover the dish with foil.

Preheat your oven to 375°F (190°C) and bake the lasagna for 25 minutes. Remove the foil and bake for an additional 15–20 minutes.

Let the lasagna rest for 10 minutes before slicing. Serve warm and enjoy!