Make the Crust: In a food processor combine the flour, sugar, and salt. Add the butter and pulse until pea-sized pieces appear. Add the water and pulse briefly—it will still look crumbly. Transfer the crumbs to 2 pieces of parchment paper or foil and form into 2 disks. Wrap the discs with plastic wrap and refrigerate overnight.

On a work surface lightly dusted with flour, roll out 1 disk to a circle about 1/8-inch thick. Keep rolling until the circle is at least 2 inches larger than your pan. Line the pie pan with the dough, letting the edge hang over a bit. Roll the second disk, place it on a sheet pan and chill it until you're ready to build your pie.

Arrange a rack in the center of the oven and preheat to 375 degrees F.

Make the Filling: In a medium bowl, toss the apple slices, sugar, cornstarch, lemon juice, vanilla, cinnamon, salt, and nutmeg together. Transfer to the pie shell and dot with the butter. Brush the overhanging edges of the dough with water. Carefully cover with the rolled-out top crust and pinch the edges together, turning them under all around to make a thick edge. To decorate the rim, press it all around with the back of a fork, or just pinch it to seal. With a scissors, cut a few V-vents in the center.

Slide the pie into the brown paper bag and fold the top down. Staple bag shut and place it on a sheet pan. Bake for 1 hour.

Remove the pie from the oven and cut a large circle in top of the bag. Return to the oven and bake until the crust is golden brown, about 15 minutes more.

Let the pie cool at least 30 minutes before serving. Serve warm or at room temperature.