Heat the oil in a large saucepan over medium-high heat; add the onion and jalapeño; cook, stirring until softened (about 3 minutes). Stir in the garlic, chili powder, and cumin; cook 1 minute. Stir in soup and black beans; simmer 5 minutes. Stir in the chopped cilantro. Ladle soup into bowls; top with 1 tablespoon of sour cream, avocado, and cilantro sprigs, if desired.