Step 1

For the crust: Preheat the oven to 350˚. Grease a 9-by-13-inch pan with butter. (Use an 8 x 10 pan if you'd like the layers to be a little thicker.)

Step 2

Stir together the flour, sugar, and salt. Add the butter to the bowl and use a pastry cutter to cut it all together until the mixture resembles fine crumbs. Press into the prepared pan and bake until golden around the edges, about 20 minutes.

Step 3

For the filling: Stir together the sugar and flour. Crack in the eggs and whisk to combine. Add the lemon zest and juice and mix until combined. Pour over the crust and bake about 20 minutes.

Step 4

Allow to cool in the fridge for a minimum of 2 hours, then sift powdered sugar over the top before cutting into squares.