confectioners sugar and flaky sea salt, for sprinkling
Instructions
Preheat oven to 160°C. Line a 23x23 cm baking pan with parchment paper, leaving overhang on two sides.
In a food processor or bowl, mix flour, granulated sugar, confectioners sugar, lemon zest, and salt. Add butter and pulse or mix until crumbly. Press into pan and bake for 30-35 minutes until pale golden.
While baking, prepare lemon curd: Grate ½ Tbsp lemon zest and squeeze lemons to yield 180ml juice.
In a saucepan, whisk lemon juice, sugar, eggs, yolks, cornstarch, and salt over medium heat until thickened (2-5 min). Ensure it boils for 30 sec but not more than 1 min. Remove from heat, strain, and whisk in butter, olive oil, and lemon zest.
Pour curd onto shortbread and bake for another 10-15 min until just set. Cool to room temp, then refrigerate until firm. Cut into bars and sprinkle with confectioners sugar and flaky sea salt before serving.