With the rack in the middle position, preheat the oven to 200°C (400°F). Line a baking sheet with parchment paper. On a floured work surface, roll out the dough 3 mm (1/8 inch) thick. Cut out four pieces using a Christmas-themed cookie cutter about 12 x 7.5 cm (4 1/2 x 3 inches) in size and transfer to the baking sheet. Brush the dough with beaten egg. Bake until golden, 10 to 15 minutes. Set aside.