18 oz. plain flour, sifted
12 oz. butter
6 oz. sugar

Put the flour, butter and sugar into a mixing bowl. Rub in very well with the fingertips. Knead until a smooth dough is obtained.

Brush a 10x15 baking sheet with melted butter, lightly dust with plain flour. Press out the shortbread dough on the baking sheet until all is even. Mark out in squares and prick all over with a fork.

Bake in the center of the oven at 325 for approximately 30-45 minutes or until the shortbread is golden brown. Remove, cut into squares where you had marked; sprinkle lightly with sugar. Cool on wire rack.