Preheat the oven to 375°F (190°C). Gather your baking dish, utensils, and all ingredients.

In a medium bowl, whisk the eggs together until lightly beaten. Add ricotta, 1 cup of mozzarella, and optional parmesan, mixing until creamy.

In a saucepan, warm the pre-cooked ground beef or sausage. Pour in the spaghetti sauce and let it simmer for about 5 minutes.

In a baking dish, pour 1 cup of pasta sauce evenly across the bottom.

Lay 4 uncooked lasagna noodles over the sauce. Spoon about a third of the ricotta mixture over the noodles.

Sprinkle half of the meat mixture over the ricotta layer, then add 1 cup of mozzarella cheese and another cup of pasta sauce.

Repeat with another 4 noodles, the remaining ricotta mixture, the rest of the meat, another cup of pasta sauce, and mozzarella.

For the final layer, place the last 4 noodles, pour the remaining sauce, and sprinkle the last cup of mozzarella on top.

Cover with aluminum foil and bake for 50-60 minutes. Remove foil for the last 5-10 minutes to brown the top.

Once baked, allow the lasagna to rest for 10-15 minutes before slicing. Garnish with chopped parsley.