Cook potatoes in boiling water until tender. Drain and mash with butter, salt, sugar and ginger.

Add flour a little at a time, until you have a soft, pliable dough.

Wrap in plastic wrap or a ziploc bag. Chill in refrigerator for 30 minutes.

Preheat oven to 375 F.

Using a mandolin, slice the apples.

Toss apples with 3 tablespoons of the flour, brown sugar and nutmeg.

On a well floured board, knead flour into the dough so it is not sticky, about 1/2 cup.

Divide dough in half, with one half being slightly larger.

On a well floured board and with flour sprinkle on top, take the smaller half and knead into a ball.

Spray a pie plate well with non stick spray.

Transfer the ball of dough to the pie plate. Sprinkle a little flour on top and using your fingertips, press the dough into the pie plate on the bottom and up the sides.. Use floured hands and add more flour as needed.

Add apples on top.

Sprinkle 2 tablespoons flour on top.

On a well floured board, roll out the larger half of the dough to a large circle to cover the cake, adding more flour as needed.

With the help of a dough scraper, fold the dough in half and transfer to pie plate.

If the dough sticks together, using well floured hands, press the dough out until it is smooth on top and is sealed with the bottom crust at the edges.

Brush the top with milk and sprinkle with sugar.

With a sharp knife, make an X in the middle.

Bake for 1 hour.

Chill completely before slicing.