in a glass bowl, combine the mole sauce, apple cider vinegar, and 1/2 cup of the vegetable broth. Stir well until fully combined.
In a soup pot (or high-sided pan) heat the corn oil over medium heat, then saute the yellow onion until translucent (4 to 5 minutes). Add the garlic, cumin, ancho powder, cinnamon, and 1/2 teaspoon salt to the onions and continue cooking, stirring often, for 1 minute.
Add the mole sauce mix, black beans, and the rest of the vegetable broth to the pot and stir well. Bring the soup to a quick boil, then reduce the heat to medium-low and allow it to simmer for approximately 15 minutes.
About 5 minutes prior to the end of the simmer, add the bittersweet chocolate, stirring often to allow it to melt. Add additional salt and pepper, to taste.
Serve with black beans whole or transfer the soup to a blender and process the soup to your desired consistency. Top with sour cream or crema (optional).