Slice cold butter into cubes. In a food processor, add flour and cubed butter. Pulse until butter is the size of small peas. Alternately, use a fork or pastry blender to incorporate butter into flour.
Add the remaining ingredients to your flour mixture - ground almonds, confectioner's sugar, vanilla sugar, and salt. Mix until combined. Dough should be crumbly, but hold together when pinched between two fingers. If you're having trouble getting your dough to come together, add up to a tablespoon of water and mix until a dough forms.
Toss dough out onto wax paper or parchment. Form into a disc, wrap, and refrigerate for one hour (up to 24 hours).
Preheat oven to 350 degrees and line a baking sheet with parchment paper.
Scoop dough using a medium cookie scoop (1.5 tablespoons) and shape into a crescents with your hands. Work quickly - your hands will warm the dough, so try to handle as little as possible.
Place crescents 2 inches apart on a lined baking sheet. Bake for 12-14 minutes, or until edges are lightly browned.
Meanwhile, combine dusting ingredients - confectioner's sugar and vanilla sugar in a small bowl.
Immediately upon removing cookies from the oven, top each cookie generously with prepared dusting sugar.
Transfer to a cooling rack and allow to cool completely before storing.
*If you do not have vanilla sugar on hand, it can be purchased on Amazon, or you can make your own using vanilla extract.
How to make vanilla sugar: In a food processor, combine ¼ cup of granulated sugar with ½ teaspoon of vanilla extract. Spread it out to dry. Once dried, the sugar will be clumpy. Transfer back to the food processor and pulse until you have a sugar consistency again.
One packet of vanillezucker/vanillinzucker contains about 1 ½ teaspoons of vanilla sugar. To make 24 cookies with this recipe, you will need 3 packets of vanilla sugar, or 4 ½ teaspoons.
Almonds can be substituted with walnuts or hazelnuts instead.