Heat oil in large Dutch oven over medium heat. Add pepper and onion; cook until vegetables are tender, about 8 minutes. Stir in tomatoes; cook, stirring occasionally, for 5 minutes.
Add zucchini, yellow squash, jalapeño, chili powder, cumin, sugar and salt; cook 1 minute. Add broth, black beans, corn and pinto beans. Simmer, uncovered, 20 minutes.
To serve, ladle chili into bowls. Sprinkle with cilantro if desired. Makes 10 servings.