Chocolate-Dipped Shortbread

Instructions

1. Prepare the dough
   In a medium bowl, whisk together the flour, cornstarch, and salt. In a separate large bowl, beat the softened butter and sugar with an electric mixer until pale and fluffy, about 3 minutes. Add the vanilla extract and mix until combined. Gradually add the flour mixture, mixing on low speed until just incorporated. Be careful not to overmix.
2. Shape and chill the dough
   Turn the dough out onto a lightly floured surface and gently knead it a few times until smooth. Shape into a rectangle about 1-inch thick. Wrap in plastic wrap and refrigerate for at least 30 minutes or up to 24 hours.
3. Prepare for baking
   Preheat the oven to 325°F (165°C). Line two baking sheets with parchment paper. Remove the dough from the refrigerator and let it sit at room temperature for about 5 minutes to slightly soften.
4. Cut and bake the shortbread
   On a lightly floured surface, roll the dough to about 1/4-inch thickness. Use a knife or cookie cutter to cut into your preferred shapes (traditional fingers or rectangles work well for dipping). Transfer the cookies to the prepared baking sheets, spacing them about 1 inch apart. Pierce each cookie several times with a fork to prevent them from puffing up. Bake for 20-25 minutes, until the edges are just barely golden. Allow to cool completely on the baking sheets.
5. Prepare the chocolate coating
   Place the chopped chocolate, 2 tablespoons of butter, and vegetable oil in a heatproof bowl set over a pot of barely simmering water (make sure the bottom of the bowl doesn't touch the water). Stir occasionally until completely melted and smooth. Remove from heat and let cool slightly until the chocolate is still fluid but not hot.
6. Dip the cookies
   Line a baking sheet with parchment paper. Dip each cooled shortbread cookie halfway into the melted chocolate. Allow excess chocolate to drip off, then place on the parchment-lined baking sheet. If using, sprinkle a tiny amount of flaky sea salt on the chocolate portion while still wet. Let the chocolate set completely at room temperature or place in the refrigerator for 15 minutes to speed up the process.