In a large skillet, heat two tablespoons of olive oil over medium heat for about 2 minutes. Add the finely chopped onion and sauté until translucent, roughly 3-4 minutes. Incorporate the minced garlic and cook for an additional minute until fragrant. Stir in the ground beef, breaking it apart as it browns, about 5-7 minutes. Mix in the canned tomatoes, tomato paste, and Italian seasoning, simmering for 15-20 minutes until the sauce thickens, stirring occasionally.

While the sauce is simmering, in a mixing bowl, combine the ricotta cheese, one egg, grated Parmesan, and chopped fresh basil. Whisk everything together until smooth and creamy, about 2 minutes.

If using traditional lasagna noodles, bring a large pot of salted water to a rolling boil. Carefully add the noodles and cook according to package instructions, usually about 8-10 minutes, until al dente.

Preheat your oven to 375°F (190°C). In a 9x13-inch baking dish, spread a thin layer of the sauce on the bottom. Layer three noodles evenly, followed by half of the cheese mixture, and then one-third of the remaining sauce. Repeat this layering twice more: noodles, cheese, sauce, finishing with a final layer of noodles topped with the last of the sauce. Sprinkle shredded mozzarella cheese generously on top.

Cover the baking dish with aluminum foil, ensuring it doesn't touch the cheese, and place it in the preheated oven. Bake for 25 minutes, then remove the foil and bake for an additional 15 minutes.

Once out of the oven, let the lasagna rest for 10-15 minutes; garnish with freshly chopped parsley and serve warm.