Black Bean Taco Soup

Taco Soup is one of my favorite things to cook. My recipe has evolved over the last few years, and here is the current procedure:
1/2 pound sausage
1/2 pound hamburger
1 tablespoon baking chocolate (yes, really)
1 teaspoon cumin
1 teaspoon chipotle pepper -- ground
1 large white onion -- chopped
14 ounces crushed tomatoes
14 ounces diced tomatoes (sometimes I double this)
14 ounces black beans, canned (sometimes I double this)
1 1/2 cups beef broth,
reduced salt
1 tablespoon buttermilk powder (or a packet of dry ranch dressing mix)
1/2 teaspoon salt
6 ounces sour cream, light
1 avocado
1/2 cup cheddar cheese -- shredded
2 tablespoons cilantro -- fresh (optional)

Brown the sausage and hamburger, adding the chocolate, cumin, and chipotle pepper when it's about half browned, then adding the onion for the last few minutes.
Place sausage, hamburger, onion, tomatoes, beans, broth, buttermilk powder, and salt in crockpot. Cook on high for two hours or on low for four hours.
Garnish individual bowls with sour cream, sliced avocado, cilantro (optional) and grated cheese.

Some people like to put tortilla chips on top, but we feel there are enough carbs in here already!