Lemon Bars with Shortbread Crust

Method

1. Heat the oven to 350°F and line a 9-inch square pan with a parchment sling. Stir the crust flour, crust sugar and salt into the melted butter, press it firmly into the pan, and bake 18 to 20 minutes, until pale gold at the edges.
2. While the crust bakes, rub the lemon zest into the filling sugar with your fingertips until it is fragrant and damp like wet sand. Whisk the flour into the zested sugar, then whisk in the eggs and lemon juice until smooth.
3. Pour the filling onto the hot crust and return the pan to the oven. Bake 20 to 25 minutes, until the edges are set and the center no longer ripples when you nudge the pan.
4. Cool on a rack for 1 hour, then chill at least 2 hours. Lift out on the sling, cut into 16 bars with a hot knife wiped clean between cuts, and dust with sugar just before serving. Keep refrigerated up to 4 days.