Preheat oven to 170 degrees Celsius. Grease and line a baking dish with parchment paper.

Make make the crust: combine the flour, powdered sugar, salt and butter in a bowl, and use your hands to mix until a crumbly dough forms.

Transfer the dough to the prepared pan, and use your hands to press it against the bottom and about 2 cm up the sides. Poke the bottom with a fork

Bake for 20 minutes, until light golden brown

While the crust is baking, make the lemon filling: in a bowl whisk together the eggs and egg yolk. Add the granulated sugar, lemon juice, lemon zest and a pinch of salt, and whisk until combined. Whisk in the flour until just combined.

When the crust is done baking, remove it from the oven. Pour the lemon filling over the crust and carefully return it to the oven for 25 minutes, until the filling no longer jiggles and the centre is mostly set.