Heat a large nonstick skillet over medium-high heat. Coat pan with cooking spray. Add beef to pan; cook 4 minutes or until browned, stirring to crumble. Add onion and garlic to pan; cook 2 minutes, stirring frequently. Add cumin, chili powder, and chipotle chile powder, and cook 30 seconds. Stir in ketchup, beans, and tomatoes; cook 6 minutes or until slightly thickened. Spoon about 2/3 cup beef mixture over 6 bottom bun halves, and top each with 1 tablespoon cheese and 2 pickles. Top with the remaining bun halves.