1 ⅔ cups confectioner's sugar, divided, plus extra for dusting
1 tablespoon flour
1 tablespoon orange zest
½ teaspoon almond flavoring
2 egg whites, room temperature
Directions
In a large bowl, combine the almond flour with 1 ⅓ cups of sifted confectioner's sugar, the plain flour, the orange zest, and the almond flavoring.
Using a stand mixer or an electric whisk, beat the egg whites until they form stiff peaks. Gently fold the egg whites into the almond flour mixture, until a dough has formed. Cover the dough and leave it for at least 2 hours, ideally overnight.
Preheat the oven to 325 F and prepare a large baking tray with a non-stick mat or baking paper, and add the remaining ⅓ cup confectioner's sugar in a bowl.
Lightly dust a clean surface with confectioner's sugar and then, using your hands, roll the dough out into a log. Using a sharp knife, gently cut cookies from the log, roughly ⅓ to ½ inch thick.
If you would like, shape the cookies into a rough oval shape (the classic shape of the ricciarello), and then coat them well on both sides with the confectioner's sugar in the bowl.
Place the finished cookies on the prepared baking sheet, and then bake them for 12 minutes until the surfaces are cracked. Leave the cookies to cool completely before serving.