THAW pastry sheets at room temperature 30 min. Preheat oven to 400°F. Line baking sheet with aluminum foil. Spray foil with vegetable cooking spray.
COMBINE bananas and syrup in bowl. Mash bananas slightly with fork.
UNFOLD 1 pastry sheet on lightly floured surface. Cut pastry in half lengthwise. Roll each piece into 15"x5" rectangle. Cut each rectangle crosswise to make 3 (5") squares. Repeat with remaining pastry sheet.
SPOON banana mixture into center of pastry squares. Fold corners to center on top of filling and twist tightly to seal. Place pastries on baking sheet.
MIX sugar and cinnamon. Brush pastries with milk and sprinkle with sugar mixture.
BAKE 15 min. or until golden. Serve warm.