For the Apple Gingerbread Pockets, mix the apples with the gingerbread spice and birch sugar in a bowl. Cut the puff pastry into equal-sized rectangles and cut half of the rectangles crosswise.
Beat 1 egg and brush the edges of the uncut dough pieces. Spread the apple-gingerbread mixture in the center of the squares. Place the cut part on top and press lightly on the edges.
Brush with the remaining egg and bake in a preheated oven at 180 °C for 15-20 minutes until the apple-gingerbread pastries are golden.