1. In a food processor, combine flour, confectioner’s sugar, nougat powder, cocoa, and margarine and process into a crumbly mixture. Add egg white and process. Dough should still be crumbly and not form a ball.
2. Gather up all the crumbs and press them into a ball with your hands. If the dough is too dry, add a little cold water. Wrap the dough ball in plastic wrap and refrigerate for one and a half hours.
3. Place dough between two sheets of Gefen Parchment Paper and roll out thin. Freeze rolled-out dough for one hour.
4. Preheat oven to 320 degrees Fahrenheit (160 degrees Celsius). After freezing, cut dough into 1- and- 1/2-inch (4-cm) squares, or 1- to 1- and- 1/2-inch (3- to 4-cm) circles. Place cookies on a baking sheet lined with parchment paper or a silicone baking mat.
5. Bake for 18 to 20 minutes until lightly browned. Let cool completely.