In a large skillet over medium heat, add the ground beef and chopped onion. Cook for about 5-7 minutes until the beef is browned and the onion is soft. Stir in the minced garlic, oregano, basil, salt, and pepper; sauté for an additional minute until fragrant, then drain any excess fat to keep the soup rich but not greasy.

Transfer the beef mixture into your slow cooker. Pour in the beef broth and crushed tomatoes, then stir to combine all the ingredients thoroughly.

Break the lasagna noodles into smaller pieces and add them to the slow cooker. Gently push the noodles down into the liquid. Cover and set your slow cooker to cook on low for 4-6 hours, or high for 2-3 hours, stirring once halfway through if possible.

When the noodles have reached that perfect tender doneness, open the slow cooker lid and add the ricotta cheese. Stir well to incorporate it throughout the soup.

Ladle the rich and hearty soup into bowls, generously topping each serving with shredded mozzarella and grated Parmesan cheese. If desired, sprinkle some fresh basil leaves on top.