Makes 12 cookies
(1 stick) unsalted butter, at room temperature, plus more for the pan
all-purpose flour, spooned and leveled, plus more for pressing in the dough
pure vanilla extract
semisweet chocolate, chopped
- Heat oven to 350° F. Butter an 8-inch round cake pan and line with a circle of parchment. In a large bowl, whisk together the flour, cornstarch, and salt; set aside.
- Using an electric mixer, beat the butter, sugar, and vanilla on medium-high until light and fluffy, 2 to 3 minutes.
- Reduce mixer speed to low and gradually add the flour mixture, mixing until just combined (do not overmix).
- With floured fingers, press the dough into the prepared pan and prick all over with a fork.
- Bake until golden and firm, 30 to 40 minutes. Let cool.
- In a small microwave-safe bowl, microwave the chocolate in 30-second intervals, stirring between each, until melted and smooth. Drizzle it over the cooled shortbread and refrigerate until set, 15 to 20 minutes.
- Turn the shortbread out of the pan and, using a serrated knife, cut into 12 wedges.