Heat olive oil in a large pot over medium heat.
Add diced onion and garlic; sauté until translucent and fragrant, about 3-4 minutes.
Add ground Italian sausage and ground beef; cook until browned, breaking up meat with a spoon.
Stir in Italian seasoning, kosher salt, and pepper.
Pour in marinara sauce, beef broth, and crushed tomatoes; bring to a simmer.
Add broken lasagna noodles to the pot and cook until noodles are tender, about 10 minutes.
Stir in heavy cream and shredded mozzarella, romano, and parmesan cheeses until melted and creamy.
Ladle soup into bowls; garnish with fresh parsley, shaved parmesan, and optional ricotta cheese.
Serve hot and enjoy your cozy lasagna soup.