Fill a large pot with salted water and bring it to a rolling boil. Cook the lasagna noodles according to the instructions on the package until al dente. Drain the noodles and set them aside to cool.

Heat a tablespoon of olive oil in a skillet over medium heat. Add the ground beef and cook, breaking it apart until it’s nicely browned. Drain any fat from the pan. Stir in the marinara sauce, diced tomatoes, and Italian seasoning. Let this mixture simmer for about 10 minutes. Taste and adjust seasoning with salt and pepper as needed.

In a bowl, whisk together the ricotta cheese, egg, and a quarter cup of grated Parmesan until the mixture is smooth and creamy. Set aside.

Preheat the oven to 375°F (190°C). In a 9x13-inch baking dish, start by spreading a thin layer of the meat sauce at the bottom. Lay down about three noodles on top. Spread half of the ricotta mixture evenly over the noodles, then sprinkle with a third of the mozzarella cheese. Add another layer of meat sauce over the cheese. Repeat these layers one more time: noodles, ricotta, mozzarella, and sauce. On the final layer, place the remaining noodles and cover them with the remaining meat sauce, mozzarella, and Parmesan cheese.

Cover the dish tightly with foil and bake for 25 minutes. Afterward, remove the foil and continue baking for another 20 minutes until the cheese on top bubbles and gains a golden hue.

Once baked, let the lasagna rest for 10 minutes before slicing. Finish by garnishing with fresh basil or parsley if you like.