Preheat the oven to 375°F (190°C).

In a large pot of boiling salted water, cook the lasagna noodles until al dente. Drain and set aside.

In a skillet over medium heat, brown the ground beef. Add salt, pepper, and Italian seasoning, cooking until the beef is browned, then stir in the marinara sauce. Let it simmer for a few minutes.

In a separate bowl, combine ricotta cheese, the egg, and half of the mozzarella and Parmesan cheeses. Mix until smooth.

Spread a thin layer of the meat sauce at the bottom of a 9×13 inch baking dish. Lay three noodles across.

Spread half the ricotta mixture on top.

Add a layer of meat sauce, followed by mozzarella.

Repeat the layers until you run out of ingredients, ending with sauce on the top.

Sprinkle the remaining mozzarella and Parmesan cheese on top.

Cover with foil and bake for 25 minutes.

Remove the foil and bake for another 20 minutes until the cheese is bubbly and golden.

Let it cool for 10 minutes before slicing into it. Garnish with fresh parsley if desired.