4 tablespoons butter, softened
1/2 cup confectioner’s sugar (powdered)
2 teaspoons fresh orange zest
1/2 teaspoon vanilla extract
1/8 teaspoon salt
2 egg whites
1/2 cup all-purpose flour
Beat the butter, sugar, orange zest, vanilla extract, and salt on medium-high until light and fluffy, about 4 – 5 minutes. Add the egg whites, one at a time, to the butter. Gently fold in the flour and refrigerate for 45 minutes.
Preheat an oven to 350F. Line 2 baking sheets with parchment paper. Fill a pastry bag with the batter and pipe into 1/3-inch wide, 2 1/2-inch long cookies. Bake them for 10 minutes until they are light golden brown. Cool the cookies on the baking sheet for seconds, and then transfer them to a wire rack to cool.