Chef John's Lemon Bars

Step 1

Set an oven rack to the middle position and preheat the oven to 350 degrees F (175 degrees C). Lightly grease an 8x8-inch baking dish.

Step 2

Make crust: Use the back of a spatula or wooden spoon to mash flour and butter in a large bowl until thoroughly combined. Mix in confectioners' sugar, vanilla, and salt until mixture resembles slightly crumbly cookie dough. Moisten your fingers with a little water and press dough into the bottom of the prepared baking dish. Use a fork to prick holes all over crust.

Step 3

Bake on the middle rack in the preheated oven until edges are barely golden brown, about 22 minutes. Set aside.

Step 4

Make custard: Beat together eggs and egg yolks in a medium bowl until combined. Whisk in white sugar and flour until smooth. Add lemon juice and zest; whisk for 2 minutes. Pour over warm crust.

Step 5

Bake on the center rack until custard is set and the top has a thin white sugary crust, about 25 minutes. Let cool completely before cutting into bars.

Step 6

Dip a knife into very hot water, then run the blade around the edges and cut into 16 squares. Dust bars with confectioners' sugar.