In a large skillet, heat a drizzle of olive oil over medium heat. Sauté the chopped onion until translucent, about 5 minutes, then add minced garlic and cook for an additional minute. Stir in the ground beef and ground pork, browning thoroughly, about 8-10 minutes. Add diced tomatoes and tomato paste, followed by sugar, dried basil, oregano, red pepper flakes, salt, and pepper. Let this simmer for 30 minutes until thickened.

While the meat sauce simmers, combine ricotta cheese in a mixing bowl with the egg, a generous pinch of salt, and freshly cracked pepper. Mix until smooth and creamy.

Preheat your oven to 375°F (190°C). Grease a 9x13 inch baking dish. Start by spreading a layer of the meat sauce on the bottom. Place a layer of uncooked lasagna noodles on top, followed by half of the ricotta mixture and a generous layer of mozzarella cheese. Repeat this layering process.

Finish with a top layer of remaining meat sauce, mozzarella, and a sprinkle of grated Parmesan cheese.

Cover the baking dish tightly with aluminum foil and bake for 45 minutes. Remove the foil and bake for an additional 15 minutes until the cheese is bubbling and golden.

Allow the lasagna to rest for at least 15 minutes before slicing. Cut into squares and serve.