Preheat oven to 350°F. Line two baking sheets with parchment paper.
Whisk confectioners' sugar and vanilla sugar in a shallow bowl for coating; set aside.
Combine flour, ground almonds, granulated sugar, and salt in a large bowl.
Cut in the cold butter and add vanilla extract. Rub with fingertips or use a pastry cutter until the dough clumps.
Press dough into a disk, wrap, and chill 20 minutes to firm slightly.
Pinch off small tablespoon portions. Roll into short logs, taper the ends, and curve into crescents.
Arrange on prepared sheets and bake 12–14 minutes, until set with lightly golden tips.
Cool 2 minutes. Gently toss warm cookies in the vanilla sugar mixture to coat.
Transfer to a rack to cool completely. Dust again before serving if you like.