Best Shortbread ever..
40z icing sugar
80z butter(I use a block of Stork margarine)
80z plain flour
40z cornflour
pinch of salt
Switch your oven on, trial and error, mine does at 120. Cream marg and icing sugar until soft and fluffly, gradually add plainflour, cornflour and salt. Roll out on floured board, cut into shapes and cook for 12 minutes. Place on wire rack to cool. Dredge with caster sugar whilst still hot.
Quick and easy, foolproof and very very delicious.