Place the flour in a mixing bowl. Add the remaining ingredients and knead everything with a mixer (dough hook) first on the lowest setting, then on the highest setting to form a smooth dough, adding 1 tbsp of water if necessary. Press the dough flat, cover and place in the fridge for approx. 1 hour. 
Line a baking tray with baking paper. Preheat the oven. Top and bottom heat: approx. 180 °C / 360 °F ; hot air / fan: approx. 160 °C / 320 °F.
Shape the dough in portions into pencil-thick rolls, cut into 4-5 cm long pieces, roll the ends a little thinner, shape into croissants, place on the baking tray and bake for 10-11 minutes. Remove the vanilla crescents with the baking paper from the baking tray and push them together on the paper. Sieve the powdered sugar, mix with the vanilla sugar and sprinkle over the hot crescents immediately after baking. Leave the vanilla crescents to cool and then sprinkle again.