Preheat your oven to 375°F (190°C) and prepare baking sheets with parchment paper.

In a bowl, combine flour, salt, sugar, and diced butter. Blend until coarse crumbs form. Gradually add cold water until dough holds together. Chill for 15 min.

Peel and dice apples, mix with brown sugar, cinnamon, lemon juice, and cornstarch. Let sit for 10 min.

Roll out dough to 1/8-inch thick on a floured surface. Cut into circles, needing two per cookie.

Place half the circles on the baking sheet, spoon filling in center, top with remaining circles, and press edges to seal.

Bake cookies for 15-20 minutes until golden brown.

Allow to cool for 5 minutes on baking sheet before transferring to wire rack. Dust with powdered sugar if desired.