In a large soup pot or Dutch oven, cook and crumble the sausage and ground beef over medium-high heat. Add the onions and garlic, cooking until softened. Stir in Italian seasoning and red pepper flakes.

Add tomato paste, diced tomatoes with their juice, chicken broth, salt, and pepper. Stir well and bring to a simmer over high heat. Once boiling, lower the heat to medium and add the pasta. Cook until noodles are tender, about 8-10 minutes.

While the pasta cooks, combine ricotta, Parmesan, and Mozzarella in a small bowl. Once noodles are cooked, remove the soup from heat and stir in the cheese mixture.

Ladle the soup into bowls and top each with a generous scoop of the cheese mixture. Serve hot, garnished with extra Parmesan if desired.