Cook Noodles: Bring a large pot of salted water to a boil. Add the lasagna noodles and cook according to package instructions (8-10 minutes). Drain and rinse under cold water. Set aside.

Prepare Meat Sauce: Heat olive oil in a skillet over medium heat. Add ground beef and brown for 5-7 minutes. Stir in marinara sauce, diced tomatoes, and Italian seasoning. Let simmer for 10 minutes, seasoning with salt and pepper to taste.

Mix Ricotta Filling: In a bowl, combine ricotta cheese, beaten egg, and grated Parmesan cheese until smooth and creamy.

Assemble Lasagna: Preheat oven to 375°F (190°C). In a baking dish, spread a layer of meat sauce, add noodles, half of the ricotta mixture, a third of the mozzarella, and more meat sauce. Repeat layers, ending with noodles topped with remaining meat sauce and mozzarella.

Bake: Cover with foil and bake for 25 minutes. Remove foil and bake for another 20 minutes until bubbly and golden brown.

Rest and Serve: Let lasagna rest for 10 minutes. Garnish with fresh basil or parsley before slicing and serving.