For the dough
150g butter at room temperature
½ cup (100g) sugar
2 cups (240g) flour
pinch of salt
1 teaspoon baking powder
For the filling
1 cup (200g) sugar
¼ cup lemon juice
¼ cup (30 g) flour
1 teaspoon finely grated lemon rind
½ teaspoon baking powder
Whip the butter and sugar in a bowl until you obtain a creamy blend.
Sift the flour, the salt and baking powder into the bowl and mix well to make a soft dough.
Add some water if necessary.
Wrap in polythene and chill for half an hour.
Roll out to a rectangle over a floured surface. Place it on a 30x20 cm baking tin without greasing.
Bake in a moderately hot oven for 10 minutes. Take it out of the oven and spread the filling over it. Put it back in the oven and bake for 15 more minutes or until golden brown.
Take out of the oven and cool. Cut the bars and remove from the tin. Serve them sprinkled with some caster sugar.
Filling: Whisk the eggs with the sugar, the lemon juice, the flour, the baking powder and the grated lemon rind. Blend well.