Preheat your oven to 375°F (190°C).
Cook the lasagna noodles according to package instructions until al dente. Drain and set aside.
In a large skillet, over medium heat, cook the ground beef, Italian sausage, and chopped onion until browned and cooked through. Add minced garlic, and cook for an additional minute.
Stir in the marinara sauce, Italian seasoning, salt, and black pepper. Simmer for about 5 minutes.
In a mixing bowl, combine ricotta cheese, half of the grated Parmesan cheese, and ½ cup of shredded mozzarella cheese. Mix until well combined.
To assemble the lasagna, spread a thin layer of the meat sauce on the bottom of a 9x13 inch baking dish. Place 4 lasagna noodles over the sauce.
Spread half of the ricotta mixture over the noodles, followed by a layer of meat sauce. Add ⅓ of the remaining mozzarella cheese.
Repeat the layering process: noodles, ricotta mixture, meat sauce, and mozzarella cheese. Finish with a final layer of noodles, the remaining meat sauce, the rest of the mozzarella, and the crumbled bacon on top.
Cover the baking dish with aluminum foil and bake in the preheated oven for 30 minutes.
After 30 minutes, remove the foil and sprinkle the remaining Parmesan cheese over the top. Bake uncovered for an additional 15-20 minutes until bubbly and golden.
Remove from oven and let it cool for 10 minutes before slicing. Garnish with fresh parsley before serving.