These soft, buttery orange cookies are flavored with orange zest and orange juice, and iced with a sweet orange glaze. Their old-fashioned flavor will remind you of your grandma's kitchen!
Preheat oven to 350 degrees F. Line two baking pans with parchment paper or silicone baking mats; set aside.
Make the Cookies: In a medium bowl, whisk together the flour, baking powder, and salt; set aside.
Using an electric mixer on medium speed, cream together the butter and the orange zest-infused sugar until light and fluffy, about 3 minutes. Add the egg and orange and mix until combined, scraping the sides of the bowl as needed. Reduce the mixer speed to low and gradually add the dry ingredients, mixing until just combined. If the dough seems a little on the soft side, refrigerate it for up to 30 minutes.
Using a medium cookie scoop (or 2 tablespoonfuls), scoop out the dough and roll them into balls, placing them 2 inches apart on the prepared cookie sheets. Bake for 10 to 12 minutes, or until very lightly browned around the edges, but still pale in the middle. Let cool for 5 to 10 minutes on the cookie sheet, and then remove to a cooling rack to cool completely.
Make the Sweet Orange Glaze: Whisk together the powdered sugar, orange zest, and enough orange juice to achieve the desired consistency (less juice for a thicker glaze, more for a thinner one). Spread glaze over top of the cooled cookies, and allow to set at room temperature for at least 30 minutes. Store at room temperature in an airtight container (divide layers with wax paper so the cookies don't stick together).