Hungarian Kifli – Walnut-Filled Crescent Cookies

Ingredients

For the Dough

• 2½ cups all-purpose flour
• 1 cup unsalted butter, softened
• ½ cup powdered sugar
• 1 egg yolk
• ½ cup sour cream
• 1 teaspoon vanilla extract
• ½ teaspoon baking powder
• Pinch of salt

For the Walnut Filling

• 1½ cups finely ground walnuts
• ½ cup granulated sugar
• 1 egg white
• 1 teaspoon vanilla extract
• 1 teaspoon lemon zest
• 2 tablespoons apricot jam

For Finishing

• 1 cup powdered sugar
• 1 packet vanilla sugar, optional