http://www.finecooking.com/recipe/orange-butter-cookies-with-grand-marnier-glaze
In a medium bowl, whisk the flour, baking powder, and salt. In a stand mixer fitted with the paddle attachment, beat the butter, sugar, and zest on medium speed until well blended, about 2 minutes. Add the egg yolks one at a time, mixing until blended after each addition. Add the vanilla extract along with the last yolk. Mix until well blended, about 1 minute. Add the flour mixture and mix on low speed until moist clumps form, about 1 minute.
Turn the dough out onto a work surface and divide into 2 equal piles on sheets of plastic wrap. Using the plastic as an aid, knead into a smooth dough, shape into flat 5-inch disks, and wrap in the plastic. Refrigerate until chilled, about 30 minutes. (The dough can be refrigerated for up to 3 days or frozen for up to 1 month.)
Position a rack in the center of the oven and heat the oven to 350°F. Line 2 or more cookie sheets with parchment or nonstick baking liners.
Working with one disk at a time, roll the dough between lightly floured parchment or on a floured surface to about 1/4 inch thick. Dust with additional flour as needed. Using a 2-1/2-inch cookie cutter, cut out shapes. Arrange them about 1 inch apart on the cookie sheets. Gather, re-roll, and cut the dough scraps up to 2 more times.
Bake, one sheet at a time, until the edges are golden-brown, 9 to 13 minutes. Let the cookies cool on the sheet about 5 minutes and then transfer them to a rack to cool completely. (The unglazed cookies can be stored in an airtight container at room temperature for up to 5 days or frozen for up to 1 month before glazing.)
In a medium bowl, combine the confectioners’ sugar, Grand Marnier, cream, zest, and salt. Mix until well blended and smooth. If necessary, add more cream a few drops at a time for a thin, spreadable consistency.
Top each cookie with about 1/2 tsp. of the glaze, using the bottom of the measuring spoon to spread the glaze to within 1/4 inch of the edge.
Let sit at room temperature until the glaze is set, about 2 hours. Serve the cookies immediately or store in an airtight container at room temperature for up to 3 days.