Preheat
the oven to
160'C/325 "F/Gas 3. Grease a 33 x 23crn/13 x
9in baking tin.
Sift the sugar,
flour and salt into a bowl. With a pastry blender,
cut in the butter until the mixture resembles coarse
breadcrumbs. Press the mixture into the base of the
tin. Bake until golden brown, about 20 minutes.
Meanwhile, for
the topping, whisk the eggs and sugar together until
blended. Add the lemon rind and juice, and mix well.
Lightly whip the
cream and fold into the egg mixture. Pour over the
still warm base, return to the oven, and bake until
set, about 40 minutes. Cool completely before
cutting into bars. Dust with icing sugar.