Step 1

Place the butter and flour in to the bowl of your food processor. Pulse to combine until the mixture resembles coarse crumbs. Place the mixture in a large bowl.

Step 2

Add the ground almonds, powdered sugar, vanilla sugar, salt, and egg yolks to the mixture. Knead the dough with your hands in the bowl until it comes together, 5 min.

Step 3

Divide the dough into 4 equal pieces, shape each into a ball. Place the balls in a sealed plastic bag or covered bowl in the refrigerator for at least half an hour, up to 2 days, to develop flavor.

Step 4

Preheat the oven to 350F. Remove the dough from the refrigerator.

Step 5

Remove one ball of dough from the refrigerator. Roll it into a rope, 12 inches long. Cut the rope into 12 even pieces. Roll each piece into a 3-4 inch rope and shape it into a crescent. Place the shaped crescents onto a baking sheet lined with parchment or a non-stick baking mat, ½ inch apart. Repeat with the remaining dough, removing one ball of dough from the refrigerator at a time, until you have filled one tray.

Step 6

Bake the cookies, one tray at a time, for 11-12 min, until the tips of the crescents just start to turn a light golden brown.

Step 7

Remove the pan from the oven. (And place your second, cool tray with shaped cookies in the oven to bake, if necessary.)

Step 8

Let the baked cookies rest on the baking sheet for 2-3 minutes while you prepare your sugar mixture. Mix ½ c powdered sugar and 1 Tbsp vanilla sugar together in a shallow bowl.

Step 9

Take the warm cookies from the baking sheet and carefully coat them in the sugar mixture. Place the coated cookies on a wire rack to finish cooling.

Step 10

Repeat as needed with the remaining cookies.

Step 11

Leave the cookies out overnight to harden, and then transfer them to an air tight container to store for up to 1 week.