Place beans in a large bowl and mash coarsely with a fork or potato masher; stir in chili powder. Wrap tortillas in a damp paper towel. Microwave on high for 45 seconds, or until tortillas are soft and warm. Divide bean mixture among tortillas and spread down center of tortilla. Sprinkle cheese on bean mixture. Roll tortillas to enclose mixture. Spray a 9 by 13-inch baking dish with nonstick cooking spray Place enchiladas, seam side down, into baking dish. Cover with foil and bake at 350° for 20 minutes or until heated through. Serve warm with salsa.