In a small bowl, use your fingertips to rub the orange zest into the granulated sugar until fragrant, about 1 minute. In a large bowl or stand mixer bowl, combine the scented sugar and softened unsalted butter. Beat on medium speed until light and fluffy, about 3 minutes. Add the vanilla extract and beat for another 30 seconds.

In a separate bowl, whisk together the all-purpose flour, salt, and cornstarch (if using). Gradually add the dry ingredients to the butter mixture on low speed, mixing until just combined and the dough forms coarse crumbs.

Gently fold in the dried cranberries with a spatula until evenly distributed.

Turn the dough out onto a piece of plastic wrap. Divide the dough in half and shape each half into a log about 8 inches long and 2 inches in diameter. Wrap tightly in plastic wrap and refrigerate for at least 2 hours, or up to 4 hours, until firm. (For extra crispness, roll the log in coarse sugar before wrapping.)

Preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper.

Remove one dough log from the refrigerator. Using a sharp knife, slice into 1/4-inch thick rounds. Place slices 1 inch apart on the prepared baking sheets.

Bake for 12-15 minutes, rotating the pans halfway through, until the edges are lightly golden but centers are pale. Cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.

Repeat with the remaining dough log.

Whisk together confectioners sugar and orange juice until smooth. Drizzle over cooled cookies.