Put flour in a bowl, add sugar, salt and butter in flakes, knead to a smooth dough. Knead the crumbles and chill for about 30 minutes.
Roll out the dough with a rolling pin on a floured work surface to form a rectangle (approx. 15 x 20 cm). Cut the rolled out dough with a sharp knife into approx. 1.5 x 1.5 cm cubes. Bake the cookie cubes on a baking tray lined with baking paper in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 10 minutes.
Let the cookie squares cool down completely, pack them in bags and give them away as a gift.