Bring a large pot of salted water to a boil. Add the spaghetti and cook according to package instructions until al dente, usually about 8-10 minutes. Drain the pasta in a colander and set aside.

In a large skillet over medium heat, add the ground beef. Cook until browned, breaking it apart with a wooden spoon, about 5-7 minutes.

Add the chopped onion and minced garlic to the skillet. Sauté until the onion is translucent, about 3-4 minutes.

Stir in the crushed tomatoes, marinara sauce, oregano, basil, salt, and pepper. Bring the mixture to a simmer and let it cook for about 10 minutes, allowing the flavors to meld.

In a mixing bowl, combine the ricotta cheese, 1 cup of mozzarella cheese, ½ cup of parmesan cheese, beaten egg, and salt. Mix until well combined.

Preheat your oven to 350°F (175°C).

In a large baking dish, layer half of the cooked spaghetti on the bottom.

Spread half of the meat sauce over the spaghetti.

Dollop half of the cheese mixture over the meat sauce and spread it gently.

Repeat the layers with the remaining spaghetti, meat sauce, and cheese mixture.

Top the final layer with the remaining 1 cup of mozzarella cheese and ¼ cup of parmesan cheese.

Cover the baking dish with aluminum foil and bake in the preheated oven for 20 minutes.

Remove the foil and bake for an additional 10 minutes, or until the cheese is bubbly and golden.

Remove from the oven and let it cool for 5-10 minutes before serving. This allows the layers to set and makes it easier to cut.

Serve warm, garnished with fresh basil if desired.