Luscious lemon slice

At this time of year we always have a glut of lemons.  One thing I'll attempt for the first time is making preserved lemons - but not quite ready to yet.  This recipe from Belinda Jeffery is a voluptuously sweet way to use up some of your surplus lemons.  It is very tangy and as she herself says, it is more lemon tart than a slice.  I've varied my recipe by including coconut in the base and using less sugar in the topping.  Her photo is much prettier than mine!  Makes 20 -24 medium sized bars

base
1 cup plain flour
1/2 cup icing sugar
1 cup desiccated coconut
180g cold unsalted butter, cut into small chunks
1/2 tsp vanilla
2 tsp iced water

lemon topping
6 eggs
2 cups caster sugar
finely grated zest of 3 lemons
1 cup strained lemon juice
1/2 cup plain flour
icing sugar
chopped pistachio nuts (optional)

Preheat oven to 180 degrees C. Lightly grease and line a baking tin measuring 32x24x5 cm.
For the base, whiz flour, coconut and sugar together in food processor.  Add butter and process till it resembles fine breadcrumbs.  With processor still running add vanilla and iced water and whiz until the mixture forms a ball around the blade. Take it out and press evenly into the tin.  Gently roll a glass tumbler across the top of the dough to smooth it out.  Bake the base for about 18mins till edges begin to colour and the top is pale golden.
In the meantime, make the topping.   Beat vigorously the eggs and sugar until frothy.  Whisk in the lemon juice and zest and sift the flour over the top gently incorporating until the mixture is smooth.
When the base is ready transfer to a wire rack to cool.  Reduce oven temp to 150degrees.  Once the base has cooled, pour the filling over the base.  Return the tin to the oven and bake for another 35 - 40 mins or until the topping has set..  Place tin on wire rack to cool.
Allow the slice to cool down completely before slicing in squares or elegant diamonds.  Dust with icing sugar just before serving and sprinkle with a few chopped pistachio nuts.  Quite lovely with a dollop of thick cream....