Sift the flour 2 to 3 times. Chill the butter in the refrigerator and cut into small pieces.
Add the rest of the ingredients to the flour, and knead.
Wrap the dough in plastic wrap and chill in the refrigerator for 1 to 2 hours.
Cut the dough into fifths to make narrow logs. Cut each log into 10 even sections. Shape each section into crescent moons and arrange them on a baking sheet.
Bake in preheated oven for 12 to 15 minutes at 170℃. You may need to increase or reduce the temperature by 10℃ to adjust to your oven.
Once they are finished baking, remove the baking sheet from the oven. The cookies are fragile, so be careful not to break them!
Mix together the topping, and use a tea strainer to sprinkle the topping onto the cookies while they are still warm.
They are ready to serve once they are cool. Store them in a can or cookie jar.
Story Behind this Recipe
Vanillekipferls are an essential Plätzchen (German Christmas cookie)! I saw how to make these on TV, then tried out a bunch of recipes, and finally came up with one that I liked.
When using refined sugar, in order to make a smooth dough, let it sit overnight. If you don't have vanilla sugar, substitute by scooping out the inside of a vanilla bean and mixing it with powdered sugar. Or, you can mix the inside of the vanilla bean into the dough itself.