SUGAR-COOKIE STARS

Steps:

• Make the cookies: Sift flour, baking powder, and 1/2 teaspoon salt into a large bowl.
• Beat butter and granulated sugar with a mixer on medium-high speed until pale and fluffy, about 3 minutes. Beat in egg.
• Reduce speed to low. Add flour mixture, then vanilla. Refrigerate dough, wrapped in plastic wrap, for at least 1 hour.
• Preheat oven to 350 degrees. Roll out dough to a 1/4-inch thickness on a lightly floured surface. Cut out various star shapes using 3-to-4-inch cutters. Transfer to parchment-lined baking sheets, spacing each 1 inch apart.
• Bake until cookies are just turning gold around the edges, 10 to 12 minutes. Let cool on sheets set on wire racks for 10 minutes. Transfer cookies to racks. Let cool completely.
• Make the icing: Whisk together confectioners' sugar and egg whites with a mixer on medium speed until icing is glossy-white and holds a ribbonlike trail on the surface for 5 seconds when beater is raised, about 5 minutes.
• Transfer icing to a pastry bag fitted with a small round tip. Pipe an outline of icing around the edges, then flood each cookie with more icing to cover. Sift edible silver dust over cookies. Let cookies dry completely.