In a small bowl, mix together the granulated sugar and apple pie spice; set this aside. Separate the biscuit dough into 16 equal portions by splitting each biscuit horizontally. Flatten each piece into a thin disc, approximately 3 to 4 inches wide. In a separate bowl, stir the chopped apple pie filling with cinnamon until thoroughly coated. Place a small spoonful of the apple mixture in the center of each dough disc, leaving a border around the edge. Pull the dough edges upward and pinch them closed, forming a sealed ball. Prepare the air fryer basket by lightly oiling it or using perforated parchment paper. Arrange the filled dough balls in the basket, ensuring at least ½ inch of space between each. Air fry at 350°F for 6 to 8 minutes or until they turn golden brown. When finished, immediately dip each hot pastry into the melted butter, followed by the sugar-spice mixture. Coat completely and repeat until all are covered.