Popular throughout Europe, these shortbread cookies are of Austrian origin and their vanilla-infused flavor and melt-in-your-mouth texture are sure to win you over!
Place all of the ingredients in a large bowl and knead until thoroughly combined. Unless you're using the egg yolks the dough will be pretty dry and flaky, like shortbread cookie dough. Shape the dough into a log and wrap with plastic wrap. Chill in the refrigerator for at least an hour.
Preheat the oven to 350 degrees F.Take some of the dough out of the fridge, leaving the remaining dough wrapped in the fridge to stay cold. Cut off small pieces of the dough and shape them into crescents. Shape them into uniform sizes so they bake evenly. Place the crescents onto a non-stick or parchment-lined cookie sheet. Bake on the middle rack for 12-15 minutes (depending on the size of the crescents) or until the edges begin to turn golden.
Combine the powdered sugar and vanilla sugar. Let the cookies sit for one minute and then use a sifter to dust them with the vanilla-powdered sugar while they're still hot. Let the cookies cool completely and then give them a second dusting.Store the cookies in an airtight container in a cool place (not the fridge) and these cookies will keep for 3-4 weeks (1 week if using egg).
Notes
Vanillekipferl are shortbread cookies, meaning they're made with a high butter content and generally without the addition of egg. You'll find some recipes that call for eggs but traditionally they are not included. Adding an egg yolk or two does make the dough easier to work with, especially for less experienced bakers, but the texture is far superior without the egg; it's lighter, looser, and more delicately crumbly with an almost melt-in-your-mouth texture.