01 -
Turn on the oven to 350°F. Cover a 9x13 pan with parchment paper.
02 -
Stir together butter, sugar, salt, and vanilla. Gently mix in the flour. Press firmly into the pan.
03 -
Pop it in the oven for 20 minutes. It should barely get golden.
04 -
In a big bowl, whisk the sugar, flour, eggs, zest, and lemon juice. Pour onto hot crust.
05 -
Bake another 25 minutes, spinning the pan halfway through. Let it cool, then keep it in the fridge for 2 hours or overnight. Sprinkle powdered sugar before serving.