In a large slow cooker or a soup pot, combine the Italian Sausage, onion powder, garlic, basil, tomatoes, and tomato sauce. Stir in the chicken broth and the salt.
Place the frozen spinach in a colander and run cool water over it to thaw it out. Stir it into the soup along with the water.
Turn on the slow cooker to low heat, put the lid in place, and allow the soup to cook for six to eight hours.
Or, you can set the slow cooker to high heat and allow it to cook for two to four hours.
If you are not using a slow cooker, place the pot on the stove and bring it to a boil over medium heat. Reduce the heat to low, cover the pot with a tightly fitting lid and allow the soup to simmer for at least an hour, lifting the lid and stirring it from time to time to keep it from scorching on the bottom.
Prepare the tortellini according to the instructions on the package.
Usually, this will involve boiling a pot of water and cooking the pasta for a set amount of time.
Drain the pasta after cooking and cool it a little by running cool water over the pasta. If you are cooking ahead of time, store the pasta in the refrigerator in a tightly covered container until you are almost ready to serve the soup.
Fifteen minutes before you are ready to serve the soup, stir in the half and a half and the cooked tortellini.
Replace the lid of the slow cooker or the soup pot and allow the soup to be warmed.
Serve the Tuscan Tortellini Soup accompanied by crusty bread.
You can top it Parmesan or mozzarella cheese if you desire.