Place prepared apples and craisins in a bowl. Add 100 grams (½ cup) granulated sugar and toss until apples are coated. Cover bowl with a kitchen towel and set aside. Allow to rest at room temperature for approximately 1 hour.
Assemble the Pie
Preheat oven to 425° F
Drain macerated apples/craisins and return to original bowl - discard excess juice. Sprinkle cornstarch, brown sugar, salt, cinnamon and nutmeg over apples and toss to coat apple and craisins evenly.
Add walnuts to the bowl and toss until evenly distributed.
Pour apple mixture into the pre-rolled, unbaked pie shell and distribute the mixture evenly.
Place the top crust over the apples and crimp pie crust as desired. Using a kitchen knife, place several slits around the pie (this will allow the steam to escape while baking).
Lightly beat an egg. Brush pie crust with egg wash and sprinkle with granulated or raw sugar (approximately 1 Tbsp.)
Place pie on a sheet pan (this will catch any juices which may leak out of the pie)
Bake for 15 minutes at 425° F
Lower oven temperature to 350° F and bake an additional 25 minutes. Check crust midway through baking. Place a pie shield or foil over the crust if it is becoming too dark.
Remove from oven, place on a cooling rack and allow to rest at room temperature for at least one hour.