Heat a large pot or Dutch oven over medium-high heat. Add the Italian sausage, diced onion, and minced garlic. Break up the sausage with a wooden spoon and cook until no pink remains and the onion is soft and translucent, about 8 to 10 minutes. Drain any excess fat.

Pour in the crushed tomatoes, diced tomatoes with their juices, beef broth, 1 cup of water, diced bell pepper, basil, Italian seasoning, seasoned salt, and black pepper. Stir everything together until fully combined.

Bring the pot to a full boil over medium-high heat, then reduce the heat to medium-low. Cover the pot and simmer for 15 minutes.

Add the broken lasagna noodle pieces directly into the simmering soup. Stir gently so the noodles are fully submerged. Cover again and cook for another 13 to 15 minutes, or until the pasta is tender but still has a slight bite. Check at the 13-minute mark to avoid overcooking.

Remove the pot from heat. Stir in the fresh spinach and let the soup rest uncovered for 5 minutes. The spinach will wilt gently from the residual heat. Taste and adjust salt and pepper as needed. Serve topped with ricotta, shredded mozzarella, and fresh basil.