Combine the flour, baking powder and salt. Using a pastry cutter or your food processor, cut in the butter until the texture resembles coarse cornmeal. Stir in the milk until a soft dough is achieved.
Form the dough into a square, about 1-inch thick and refrigerate for 30 minutes. Roll out as directed.
For The Apple Dumplings and Sauce
Combine the cranberries, hazelnuts and maple syrup and stuff the center of each apple with the mixture. Top each with a pat of butter.
Roll out the pastry to 1/8-inch thick and cut into 6 squares, about 7 inches each. Place one apple in the center of each square and bring the corners up to meet in the middle. Crimp all the edges to seal well. Place the dumplings in a 9 x 13-inch baking dish and set aside while you make the sauce.
Place sugar, apple cider, lemon juice, cinnamon and remaining 4 tablespoons butter in a small saucepan and boil for 1 minute.
Pour cider sauce over dumplings. Bake for about 1 hour, spooning sauce over dumplings once or twice during baking. Serve dumplings in dessert dishes with sauce spooned over.