Using a food processor, add the flour, salt, and cinnamon and pulse to mix together. Add the cold butter and shortening, and pulse until the mixture resembles coarse breadcrumbs with pea-sized pieces of fat left.

Add the water, 1 tablespoon at a time, and pulse until the dough begins to form large clumps.

Bring together with your hands, then cut the dough in half, and shape into 1-inch thick round discs.

Wrap both in clingfilm, and chill for 1 hour.

On a lightly floured surface, roll out one of the dough discs to line a 9x2-inch round pie dish. Lightly press into the pie dish, making sure not to stretch.

Cut off the excess pastry and shape as desired. Chill until ready to use.

Gently stir together the sliced apples, sugar, flour, cinnamon, ginger, nutmeg, salt, and vanilla extract until combined. Set aside.

Preheat the oven to 200C/400F/Gas 6.

Spoon the filling into the pie crust, and discard any leftover juices.

Roll out the other dough disc to a 12-inch circle. Using a pastry wheel, or sharp knife, cut out strips about 1-inch wide. Carefully thread the strips on top of the pie, over and under one another. Press the edges into the bottom crust to seal.

Cut off any excess pastry. Lightly brush the top of the pie with the egg mixture and sprinkle with a little sugar, if desired.

Bake for 45 - 50 minutes until the apples are tender and the crust is golden brown. After the first 30 minutes of baking, cover the edge of the crust with aluminium foil to prevent excessive browning, if needed.

Allow to cool on a wire rack for at least 3 hours before serving to let the filling thicken up.