Preheat your oven to 350°F (175°C) and line baking sheets with parchment paper.

Melt the unsalted butter in a medium saucepan over medium heat, then add diced apples, lemon juice, granulated sugar, cinnamon, salt, and nutmeg. Cook until bubbling, then simmer for 5-7 minutes.

Roll out the refrigerated pie crusts to about ⅛ inch thick and cut out 24 circles.

Scoop about 1 tablespoon of the apple filling into the center of each dough circle and brush the edges with beaten egg.

Using remaining dough, create lattice strips and arrange them on top of the filled cookies.

Brush tops with the remaining beaten egg and sprinkle with a mixture of sugar and cinnamon.

Bake for 20-22 minutes until golden brown.

Allow cookies to cool on wire racks before serving.