Prepare the ingredients by adding the undrained black beans and olive oil to the slow cooker. Chop the onion and green bell pepper, mixing them with the beans. Add minced garlic, oregano, red pepper flakes, and smoked paprika.

Pour in the vegetable broth, season with salt and pepper, and add bay leaves. Stir to combine all ingredients.

Cover the slow cooker and set it to cook on high for 2 to 2.5 hours. Check for doneness after 2 hours.

Once done, remove the bay leaves and use an immersion blender to blend the soup to your desired consistency.

Ladle the soup into bowls and top with sour cream, cilantro, and avocado before serving.