Ingredients

　　3/4 cup all-purpose flour

　　2 tablespoons cornstarch

　　1/8 teaspoon double-acting baking powder

　　1 stick (1/2 cup) unsalted butter, softened

　　1/3 cup confectioners' sugar

　　1 large egg, separated, the white at room temperature

　　2 tablespoons freshly grated orange zest

　　1/4 teaspoon vanilla

　　1 tablespoon fresh orange juice

　　granulated sugar for sprinkling the cookies

　　2 ounces bittersweet or semisweet chocolate, melted and cooked slightly

　　Into a large bowl sift together the flour, the cornstarch, the baking powder and a pinch of salt. In a bowl with an electric mixer cream together the butter and the confectioners' sugar until the mixture is light and fluffy, beat in the yolk, the zest, the vanilla, and the orange juice, and stir in the flour mixture well. In a bowl beat the white until it forms soft peaks and fold it gently but thoroughly into the mixture. (The batter will have the consistency of soft dough.) Transfer the batter to a pastry bag fitted with a decorative ribbon tip and onto the buttered baking sheet pipe 1 1/2-inch lengths 1 inch apart. Sprinkle the lengths with the granulated sugar and bake the cookies in the middle of a preheated 350°F. oven for 10 to 12 minutes, or until the edges are golden. Transfer the cookies to racks and let them cool until they can be handled. Dip 1 end of each cookie into the chocolate and let the cookies dry completely on the racks.