Make the dough: In a bowl, combine flour, cold butter, powdered sugar, egg yolk, vanilla, ground walnuts, and salt. Mix until it forms a smooth dough. Chill for 30–60 minutes.
Shape the cookies: Divide dough into small portions. Roll each portion into a small log and bend into a crescent shape (kifli).
Bake: Place on a parchment-lined baking sheet. Bake at 180°C (350°F) for 12–15 minutes, until lightly golden.
Cool and dust: Let cookies cool slightly, then dust generously with powdered sugar. Serve once fully cooled.
