Mix flour, baking powder and gingerbread spice. Knead with fat in flakes, egg and sweetener to a smooth short pastry. Cover and chill for about 30 minutes, roll out the dough on a slightly floured work surface to a rectangle (about 16x20 cm) about 1 cm thick.
Cut the rectangle into 40 sticks (approx. 1x8 cm). Press 3 hazelnuts with or without skin on each stick. Put them on a baking tray lined with baking paper, whisk the milk and 1 teaspoon of water and brush the sticks with it.
Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 12-15 minutes. Let them cool down.