Preheat large skillet over low heat. Line up 6 tortillas. Divide cheese, corn, cilantro and peppers between the tortillas, then cover each with a second tortilla. Place a tortilla on the dry skillet or grill and warm until cheese is melted and tortilla is slightly golden, about 3 minutes. Flip and cook other side until golden, about 1 minute. Cut into wedges and serve. Repeat with remaining quesadillas. Serve each wedge with a dollop of cilantro yogurt "sour cream."