In a mixing bowl, combine all-purpose flour, granulated sugar, and salt. Cut in cold, cubed unsalted butter until mixture resembles coarse breadcrumbs. Gradually add cold water, mixing until the dough forms a ball.

Wrap the dough tightly in plastic wrap and refrigerate for about 30 minutes.

Preheat your oven to 350°F (175°C).

Roll out the chilled dough on a lightly floured surface to about 1/8 inch thick and transfer it to the tart pan.

In a large mixing bowl, whisk together the light golden syrup, eggs, fresh lemon juice, and lemon zest until smooth.

Carefully pour the lemony filling into the prepared pastry shell.

Bake for 40 minutes until the filling is set and the crust is golden brown.

Allow the tart to cool in the pan for at least 15 minutes before slicing.