Pulse the flour, baking powder, and salt in a food processor to combine.
Add the shortening and the butter and pulse until the mixture looks like a coarse meal.
Add the bourbon and pulse until just incorporated.
Pulse in the ice water until the dough holds together when pinched.
Turn out the dough onto a pastry mat and gather it together.
Divide into 2 pieces and gently pat each into a disk.
Filling ―
Peel the apples and slice about ¼ inch thick. Toss with the bourbon, flour, sugar, cinnamon, and nutmeg.
The build ―
Preheat oven to 400° F.
Roll out 1 disk of dough into a 12-inch round on a lightly floured surface.
Ease into a 9-inch greased pie plate. Roll out the remaining disk of dough into a 12-inch round on a lightly floured surface.
Spoon the apple filling into the prepared pie crust dot with 2 tablespoons butter.
Lay the dough round over the filling. Pinch the overhanging dough together and fold under itself; crimp the edge with your fingers or a fork. Cut a few slits in the top crust to allow steam to escape. Brush the crust with the beaten egg.
Put a baking sheet on the lowest oven rack. Bake the pie on the hot baking sheet until the crust is golden, approximately 50 minutes.
Transfer to a rack and let cool for at least 2 hours.