Preheat the oven to 375°F (190°C).
Prepare the apple filling: In a large bowl, combine the sliced apples, sugar, cinnamon, nutmeg, lemon juice, and flour.
Roll out the pie crust and cut into circles that fit your mason jars.
Layer the apple mixture into the mason jars until filled halfway.
Top with the pie crust circle, crimping the edges to seal. Cut a small slit in the top to allow steam to escape.
Brush the top of the crust with the egg wash for a golden finish.
Arrange the jars on a baking sheet and bake for 25-30 minutes or until the crust is golden brown.
Remove from the oven and let cool slightly before serving.