Preheat oven to 450°F. Spray a half sheet pan with non stick cooking spray.
Heat olive oil in a skillet over medium high heat. Cook the ground beef until browned and stir in the taco seasoning.
Lay 6 of the tortillas on the half sheet pan hanging over the edges and lay one in the center.
Sprinkle on half of the cheese followed by the ground beef, green chilies, beans, corn, and salsa. Sprinkle on the remaining cheese.
Fold the tortillas onto the filling and place another tortilla on top to completely cover the filling.
Spray the bottom of another half sheet pan with non stick cooking spray and place onto the quesadilla. Press it down and bake for 20-25 minutes. The pan on top and bottom will help it brown in the oven.