Preheat the oven to 375°F (190°C).

In a large saucepan, heat the olive oil over medium heat. Add the diced onion and sauté until soft, about 5 minutes.

Add the minced garlic and ground beef (or sausage). Cook until the meat is browned and cooked through, breaking it apart with a spoon as it cooks, about 8-10 minutes.

Stir in the crushed tomatoes, tomato paste, oregano, basil, salt, and pepper. Let the sauce simmer for about 10 minutes.

While the sauce simmers, cook the lasagna noodles according to package instructions until al dente; drain and set aside.

In a large bowl, mix together the ricotta cheese, egg, salt, and pepper until well combined.

To assemble the lasagna, spread a thin layer of the meat sauce on the bottom of the sheet pan. Layer 4 lasagna noodles on top of the sauce.

Spread half of the ricotta mixture over the noodles, add another layer of meat sauce, and sprinkle with one cup of mozzarella cheese.

Repeat the layers: noodles, remaining ricotta mixture, meat sauce, and 1 cup of mozzarella cheese.

Finish with a final layer of noodles, the remaining meat sauce, and the remaining mozzarella cheese. Sprinkle the grated Parmesan cheese on top.

Cover the sheet pan with aluminum foil and bake in the preheated oven for 25 minutes. Remove the foil and bake for an additional 20 minutes or until the cheese is bubbly and golden.

Remove from the oven and let it sit for 10 minutes before slicing. Garnish with fresh basil if desired and serve.