Preheat the oven to 180ºC.
In a food processor, blits the biscuits, then add the butter, blend until the crumbs clump together, add some hot water if it does not.
Press into a greased pie dish.
Gently stir the yolks, condensed milk, juice and zest until well combined.
Pour over the crumb base.
Bake for 20 - 25 minutes or until firm to the touch. Allow to cool slightly.
Meanwhile, Beat the egg whites, castor sugar and lemon juice until soft peaks form.
Fold in some extra lemon zest or vanilla essence.
Reduce the oven temperature to 170ºC.
Gently spread onto the cooled filling and bake for a further 10 - 15 minutes or until golden.Recipe by Carey Boucher Erasmus and published in Crush online magazine