Heat oven to 375°F. Spray 13x9-inch (3-quart) baking dish with cooking spray. In 12-inch nonstick skillet, cook beef over medium-high heat 5 to 7 minutes, stirring frequently, until no longer pink; drain. Return to skillet; stir in beans, corn, tomatoes, chiles, taco seasoning mix and chili powder. Heat to simmering.