Soak the black beans overnight or 6–8 hours prior to cooking.
Heat the olive oil in a large pot over medium-high heat. Add the red onion, peppers and garlic; sauté until the onion is translucent. Reduce the heat to medium-low, and add the oregano, cumin, chipotle chilies, and adobo sauce; sauté for 1 minute. Add the cold water, bay leaf, and beans. Bring the soup to a boil, then lower to a simmer and cook uncovered for 1 1/2 to 2 hours, until the beans are tender.
Stir in the cocoa powder, orange juice, cilantro, scallions, and salt; continue to simmer for 5 minutes.