In a large bowl, combine black beans, corn, green chiles, chili powder, and cheese.
Place three tortillas on a plate sandwiched between two dampened paper towels and microwave for 30 seconds. Place the warmed tortillas on a baking sheet coated with cooking spray. Spoon the black bean mixture onto one half of each tortilla, then carefully fold over. The tortillas should stay folded, if not, press gently to get them to stick.
Repeat with the remaining tortillas until all the filling has been used. Spray the tops of the tacos lightly with cooking spray.
Bake for 10 minutes, flip, and cook another 5 minutes until the tacos are lightly browned and crispy. Serve with pico de gallo and sour cream.