Mix flour, baking powder, ginger, vanilla sugar, and cinnamon in a large bowl.
Cut butter into cubes and crumble it into the flour until the mixture resembles grated cheese – just like when making pie dough.
Add syrup, egg, and brown sugar – optionally mix the three together beforehand.
Press everything together well with your hands and form it into a clump.
Preheat the oven to 180 degrees Celsius (356 degrees Fahrenheit).
Lightly dust the table with flour and roll the dough out to 4 mm thickness – use half or a third at a time to make it easier to handle.
Get out all your best cookie cutters, cut out the shapes, and place the cookies on a baking sheet – if you want to hang the cookies, poke a hole for the string with a straw. Mine were about 5 cm in size, so I got quite a few out of the batch.
Bake the cookies in the middle of the oven for about 8 minutes.
Take them out and let them cool on a rack.
Mix powdered sugar, egg white, and vinegar together to make an icing.
Pour the icing into a piping bag, cut a small hole, and decorate the cookies – optionally make different colored icings! I think green, red, and white are the most festive.