Preheat oven to 175 degrees C.

In a medium bowl, blend together softened butter, 2 cups flour, salt and 0.5 cup sugar. Press into the bottom of an ungreased 8x11 inch pan lined with baking paper. (20x28cm)

Bake for 20 to 25 minutes in the preheated oven, or until firm and golden. It's better to overcook than undercook the crust.

Put the lemons 15 seconds in the microwave to get more juice.

In another bowl, whisk together the remaining 1.5 cups sugar and 0.25 cup + 1 tablespoon flour. Whisk in the eggs and lemon juice. Pour over the baked crust.

Bake for an additional 20-25 minutes in the preheated oven.

Cool completely before cutting it into 5cm squares. The bars will firm up as they cool.

Put icing sugar on top of it before eating.