To prepare crust, whisk flour, sugar and salt in a large bowl. Add butter and rub it in the flour mixture with your fingers until it resembles coarse sand.
Add 4 tablespoons of water and mix the dough together. Add more water, a tablespoon at a time, until the dough hold together when pitched.
Form a disc on a lightly floured surface. Fold the dough in half, press down to the original size and fold in half again. Repeat two more times until the dough becomes smooth.
Divide the dough into 2 pieces, in the ratio of 2/3 and 1/3, and form 2 discs. Wrap doughs with plastic wrap and refrigerate for about 30 minutes to chill.
To prepare apple filling, put all ingredients in a large bowl and mix until all the apples are well coated. Set aside.
Remove the large dough from the fridge. Roll it on a floured surface, until around 3mm thick. Line a greased 9-inch pie pan with the rolled dough. Make sure you leave a tiny overhang of dough.
Roll the small dough until around 3mm thick, and cut into 12 to 14 strips, each around 1/2 inch wide.
Pour the apple filling into the prepared pie shell. Lay 6 or 7 strips over the filling, evenly spaced, and then weave with the remaining strips diagonally. Fold back the edge of the shell over the edge of the lattice strips, and crimp to secure.
Mix the egg wash ingredients, and brush the dough with the mixture. Bake about 50 to 55 minutes, until the filling is bubbling and the crust is golden.
Remove pie from oven, and let it sit in room temperature for 30 minutes. Serve with vanilla ice cream.