Ingredients:
1 cup(2 sticks, ½ pound, or 227 grams) unsalted butter, room temperature
1/2 cup(100 grams) granulated sugar
1 large egg, room temperature
1 tablespoonfinely grated lemon zest
1 teaspoonpure vanilla extract
2 cups(250 grams) all-purpose flour
5 ounces(142 grams) dried currants
1/2 teaspoonbaking soda
1/2 teaspoonkosher salt
1 handfulsanding sugar
Directions:
In a large bowl, using an electric mixer on medium speed, beat the butter and sugar for about 3 minutes, until combined and creamy. Add the egg, lemon zest, and vanilla and beat until combined. Beat in the flour, currants, baking soda, and salt until just combined.
Line a rimmed baking sheet with parchment paper. Transfer about one-quarter of the dough to a piping bag fitted with a ½-inch (1.2-centimeter) star tip. Pipe small rings, about 1¾ inches (3.6 centimeters) in diameter, onto the prepared baking sheet. Repeat with the remaining dough. Freeze for about 20 minutes, until firm.
Meanwhile, heat the oven to 350°F (180°C). Line 2 rimmed baking sheets with parchment paper. Tip a little bit of sanding sugar into a small bowl. Quickly dip the cookies into the sugar to coat, then transfer them, about 1 inch apart, to the prepared baking sheets. Return the remaining cookies to the freezer.
Bake the cookies, rotating the sheets halfway through, for 13 to 18 minutes, until golden around the edges. Transfer the baking sheet to a wire rack to cool. Repeat with the remaining cookies.
Do Ahead: The cookies can be made 3 days ahead. Store in an airtight container at room temperature, or freeze for up to 2 months.