Firstly, preheat the oven to 425 degrees Fahrenheit and then prepare and place the pie crust in the pie plate, then set aside.
In a medium bowl, add 1/2 cup flour, 1/2 cup sugar, and then add 1 tsp cinnamon and 1/2 tsp nutmeg, mixing well with a spatula.
Wash and then use a vegetable peeler to remove the skins off 4-6 Granny Smith apples.
Use an apple slicer to slice the apples, then remove any harder bits and also the core. Then slice the apples in half again and place them into the bowl with the dry ingredients.
Once the apples are sliced, peeled and placed in the bowl, mix well with the dry ingredients.
Pour the apple pie filling into the prepared pie crust, then slice the butter and place the slices over the apples before adding the top crust lattice.
With extra pie crust, make crust strips and then form a lattice pattern on the apple pie.
Crack an egg and then mix it with a fork, using a pastry brush, brush the egg onto the pie crust.
Then sprinkle sugar on the top of the pie crust where the egg wash was brushed on.
Place the apple pie into the preheated oven and then bake for 30-35 minutes.
Remove the apple pie when done and then let it rest to cool before slicing.
Finally, cut the pie and serve with whipped cream and enjoy!