Lay out four tortillas on a cutting mat or board. Spread half of the tortillas with about 2 tablespoons cream cheese each. Sprinkle mango and poblano peppers over cheese, and press another tortilla on top. Brush butter over the outside of each quesadilla, top and bottom.
Grill quesadillas 5 minutes each side, or until golden brown. Remove from grill, and slice into wedges.