Heat olive oil in a large pot over medium heat. Add sausage, breaking up into bite sized pieces and cook until browned and cooked through. Add onions and cook until softened, about 6 minutes. Add garlic, oregano, and red pepper flakes. If you're using dried basil, add it at this point. Cook for about a minute. Add tomato paste and stir well to incorporate.

Add diced tomatoes, bay leaves, and chicken stock. Stir to combine. Bring to a boil and then reduce heat and simmer for 30 minutes. You can add the dry pasta to the soup in the last 8-ish minutes of cooking, or do as I prefer, and cook the pasta separately and add to individual servings. Right before serving, stir in fresh basil if you're using fresh, and season to taste with salt and freshly ground black pepper.

In a small bowl, combine the ricotta, Parmesan, salt, and pepper.

To serve, place a generous dollop of the ricotta mixture in each soup bowl, add pasta if you cooked it separately, and ladle the hot soup over the cheese. Let it sit for a minute for the cheese to get all melty, sprinkle mozzarella on top if desired and eat up.