Preheat your oven to 425°F (220°C).
Prepare the apple filling by mixing together the sliced apples, sugar, lemon juice, cinnamon, nutmeg, cornstarch, and salt in a large bowl.
Roll out your pie crust and cut it into circles that fit the tops and bottoms of your jars.
Layer your apple filling into the jars, filling them about three-quarters full.
Place a dough circle on top of each jar and crimp the edges to seal.
Brush the tops with egg wash for a golden finish.
Cut a small slit in the center of each crust to allow steam to escape.
Place the jars on a baking sheet and bake for 20-25 minutes until golden brown and bubbly.
Remove the jars from the oven and let them cool before serving.