Make the Gluten-Free Pastry:

1. Add the gluten-free flour blend and salt to the bowl of a food processor and pulse to combine.
2. Add in the cream cheese and butter and pulse 7 times.
3. Add the vinegar to the water and with the motor running pour the water mixture into the flour. Continue to process the dough until it all forms together into a ball around the blade.
4. Remove the dough from the processor and divide the dough into two portions.
5. At this point you could roll out the dough immediately on a well floured surface, or you can store the dough in plastic wrap for up to 3 days in the refrigerator (or 3 months in the freezer).

Assemble and Bake:

1. Preheat oven to 400ºF.
2. Combine the sliced apples and lemon juice in a large mixing bowl. Add in the cornstarch, brown sugar, granulated sugar, salt, cinnamon, nutmeg and vanilla and mix together. Let sit until the apples have released some of their juices, at least 20 minutes.
3. Meanwhile, on a well-floured surface, roll out 1 gluten-free pie dough to an 11″ circle. Fit the pastry in a 9” pie plate, making sure to press the pastry into the sides and the bottom. Roll out the second pastry and slice strips to make a lattice, if desired, or leave whole to make a simple double-crust pie.
4. Place the macerated apple pieces inside of the pie crust, taking care to layer the apples together, leaving very little space in between the apple pieces. Pour any remaining apple juices inside of the pie pastry. Place the pieces of butter on top of the filling and then top the pie with a lattice, or top with the rolled out pie dough with a few slits or small shapes stamped out of it to let steam escape.
5. Brush the crust with an egg wash and sprinkle with coarse sugar, if desired.
6. Bake on the lower rack, for 55-65 minutes or until the pie reaches an internal temperature of above 200ºF, and the filling should be bubbling throughout. If the pie crust is browning too quickly, lightly cover with foil.
7. Let the pie cool about at least an hour, to let the juices set up.