Preheat the oven to 375 F. In a large skillet, heat olive oil over medium-high heat. Add the onion and saute for 4-5 minutes.

Add the minced garlic and cook for up to 1 minute until fragrant.

Next, add ground beef and ground pork to the garlic and onion mixture. Cook until browned. Drain the excess fat and season with salt and pepper.

Pour in the diced tomatoes, tomato paste, sugar, basil, oregano, crushed red pepper flakes, salt, and pepper. Bring to a simmer, and cover with a lid.
Cook covered for 30 minutes, stirring occasionally. Remove from the heat.

In a large pot with boiling water, cook the lasagna noodles until al dente according to the package instructions.

In a bowl, combine the ricotta cheese, egg, dried basil, and salt. Set aside.

Grease or butter a 9x13-inch baking pan. Spread bolognese sauce just to cover the bottom of the pan.

Top with 3 lasagna noodles. Spread 1/3 of the remaining bolognese sauce on top of the noodles. Cover with 1/3 of the ricotta mixture. Then, sprinkle 1 cup of shredded mozzarella cheese. Repeat with the second layer (3 cooked lasagna noodles, 1/3 tomato sauce, 1/3 ricotta mixture, 1 cup mozzarella).

Top with the remaining 3 lasagna noodles, sauce, ricotta mixture, 2 cups mozzarella cheese, and Parmesan cheese. Cover with foil and bake in the preheated oven for 40 minutes. Then, remove the foil and cook until the cheese is melted for 10-15 minutes more, or broil for a few minutes. Slice and enjoy!