Key lime shortbread
Instructions:
- Cookies:
- 11⁄2 cups all-purpose flour;
- 1⁄2 cup confectioners’ sugar;
- 1⁄2 cup cornstarch;
- 1 cup (2 sticks) unsalted butter, at room temperature;
- 1 tablespoon key lime juice;
- 2 teaspoons finely grated lime zest.
- Glaze:
- 11⁄4 cups confectioners’ sugar;
- 2 teaspoons finely grated lime zest;
- 2 to 3 tablespoons key lime juice.
- For the cookies:
- Whisk together the flour, confectioners’ sugar, and cornstarch in a medium bowl and set aside.
- Beat the butter, key lime juice, and lime zest until creamy in a large bowl with an electric mixer set to medium speed. Add the flour mixture and beat on low speed until pea-sized clumps of dough form. Gather the clumps into a ball, place between 2 large sheets of plastic wrap, and roll to 1⁄4-inch thickness. Refrigerate until firm, at least 2 hours.
- Preheat the oven to 350°F. Line a baking sheet with parchment paper or a silicone baking mat.
- Cut the dough into 2-inch rounds (or other shapes) and arrange them 1 inch apart on the prepared baking sheet. (If the dough is so firm that it breaks when you try to cut it, let it sit at room temperature for 10 minutes.) Bake the cookies until firm and slightly golden on the edges, about 12 minutes; do not let them brown on top. Let cool on the pan for 2 minutes and then use a spatula to transfer to a wire rack to cool to room temperature.
- For the glaze: Whisk together the confectioners’ sugar and lime zest in a small bowl. Gradually whisk in enough key lime juice to make a smooth glaze that is creamy and spoonable but not runny. Spoon the glaze over the tops of the cookies, spreading it to the edges. Set the cookies aside until the glaze is hardened, about 15 minutes. Store in an airtight container at room temperature.