**Preheat the oven** to 375°F.
**Par-Bake the Bottom Crust:** Roll out the bottom crust and place it in a 9" pie pan. Poke the bottom with a fork about 10 times. Line with parchment paper and fill with pie weights (or dry beans/rice). Bake for 20 minutes. Remove from the oven, discard the weights, and bake for another 15 minutes or until golden. Set aside to cool.
**Preheat the oven** to 400°F.
**Prepare the Filling:** In a large bowl, combine the sliced apples, lemon juice, zest, sugar, salt, flour, cinnamon, nutmeg, mace, and vanilla. Stir until well combined.
**Assemble the Pie:** Add the apple mixture to the pre-baked pie shell. Dot with 5 tablespoons of butter. Lay the top crust over the filling, pinch the edges together, or use a fork to seal. Cut a hole in the center, or create a lattice top or crumb topping.
**Make the Egg Wash:** Beat the egg with 1 tablespoon of water or cream. Brush the top crust with the egg wash and sprinkle with sugar.
**Bake the Pie:** Place the pie in the oven and bake at 400°F for 30 minutes. Reduce the temperature to 350°F and bake for another 45-60 minutes until the center is bubbling. If the top starts to get too dark, tent the pie with foil.
**Cool the Pie:** Let the pie cool for about 1 hour before cutting.