In a large pot over medium heat, heat oil. Add garlic, onion, carrots, and celery. Cook, stirring occasionally, until onion is softened, about 5 minutes. Add chili powder and cumin. Cook, stirring, for 1 minute. Add chopped apple, mashed bean and tomato mixture, remaining beans, broth, and corn. Bring to boil. Reduce heat and simmer until vegetables are tender, 10-15 minutes more. Stir in salt and pepper. If using, stir in cilantro now.