I used Dorie Greenspan’s recipe from one of my favorite cookbooks, “Baking” and followed her variation for lemon sablés to infuse the sugar with orange flavor:
Orange Sablés with Cardamom
2 sticks (8 ounces) unsalted butter, at room temperature 1⁄2 C granulated sugar
Zest of 1 orange
3⁄4 C confectioner’s sugar, sifted
3⁄4 t ground cardamom (or to taste)
1⁄2 t salt, preferable fine sea salt
2 large egg yolks, at room temperature 2 C all-purpose flour
Course sugar
Working with a stand mixer, preferably fitted with a paddle attachment, beat the butter at medium speed until smooth and very creamy. Using your fingers, rub the zest of the orange into the granulated sugar until the sugar is moist and aromatic, then add this to the confectioner’s sugar, salt and butter. Beat until well blended. Reduce mixer speed to low and add the egg yolks, beating until incorporated.
In a small bowl, whisk the cardamom into the flour. Turn off the mixer and add the flour, and pulse on low speed to slowly incorporate the flour. Once incorporated, beat the flour for about 30 seconds more until the dough is uniformly moist. If flour remains at the bottom of the bowl or the sides, use a rubber spatula to work the rest of the flour into the dough. You want to work the dough as little as possible.
Gather the dough into a ball and divide it in half. Shape each piece of dough into a log about 9 inches long and wrap tightly in plastic wrap. You can use the plastic wrap to help shape the logs. Refrigerate for at least 3 hours or freeze up to 2 months.
When ready to bake, set the oven for 350 degrees and line baking sheets with parchment paper. Whisk an egg yolk until it is smooth and brush the sides of the log with the egg yolk to hold the granulated, crystal or colored sugar to the sides of the cookies. Cut into slices 1⁄4 inch to 1⁄2” thick and bake for 17 to 20 minutes or just until lightly golden on the edges.