In a skillet over medium-high heat, warm olive oil. Add ground beef and chopped onion, stirring until beef is browned and onions are translucent, about 5-7 minutes.

Sprinkle in salt, fresh ground pepper, and Italian seasoning. Stir in minced garlic and sauté for an additional minute until fragrant.

Transfer the sautéed beef and onion mixture to the slow cooker. Add crushed tomatoes, diced tomatoes, and broth. Stir everything together until well combined.

Cover the slow cooker and set it to low heat for 7-8 hours or high heat for 3-4 hours.

About 30 minutes before serving, break lasagna noodles into smaller pieces and stir them into the soup, along with grated Parmesan cheese.

In a separate bowl, mix ricotta cheese, additional Parmesan cheese, Italian seasoning, and a pinch of salt and pepper.

Ladle the soup into bowls and add a spoonful of the ricotta mixture on top before serving.