Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper.
In a large bowl, combine flour, sugar, and salt. Cut in the butter until the mixture resembles coarse crumbs. Stir in the ice water a tablespoon at a time until the dough comes together.
Roll out the dough on a floured surface into a rectangle about 1/8 inch thick.
Spread the chopped apple pie filling over half of the dough. Fold the other half of the dough over the filling, pressing the edges to seal.
Cut the dough into strips to form 'fries'. Transfer them to the prepared baking sheet.
In a small bowl, combine the beaten egg and milk to make an egg wash. Brush the egg wash over the fries.
Mix the cinnamon and sugar together and sprinkle over the fries.
Bake for 20-25 minutes or until golden brown. Allow to cool slightly before serving.
Notes
Serve with caramel sauce or a scoop of vanilla ice cream for an extra indulgent treat.