In a large skillet over medium-high heat, brown 1 pound of ground beef for about 6-8 minutes until fully cooked, stirring occasionally. Drain excess grease and transfer to the crockpot.

In the crockpot, add the browned ground beef, 1 diced onion, 1 diced red bell pepper, 14.5 ounces of crushed tomatoes, and 28 ounces of diced tomatoes. Add 2 minced garlic cloves and 2 teaspoons of Italian seasoning, then stir to combine.

Pour in 4 cups of beef broth, stirring to ensure all ingredients are distributed. Secure the crockpot lid.

Set the crockpot to cook on low for 6-8 hours or on high for 3-4 hours. Let the soup bubble gently.

When nearing completion, break 12 ounces of lasagna noodles into bite-sized pieces and sprinkle over the soup. Stir gently and cover. Cook on high for another 30-45 minutes until noodles are tender.

Ladle the soup into bowls. Top with a spoonful of ricotta cheese, sprinkle with shredded mozzarella, and finish with grated Parmesan cheese.