Spread goat cheese on tortillas. In a small bowl, gently mix together the mango,onion, jalapeno & cilantro. Spread the mixture onto one half of each tortilla. Fold the tortilla in half over the filling.
Use a large skillet over medium-high heat and cook each quesadilla until the cheese softens and the tortillas are crisp and browning (about 2 minutes). Lower the heat to medium if the tortillas are browning too much.