Cream the butter and sugar together until pale and fluffy. Work the sifted flour into the creamed mixture until it forms a firm paste.
Knead it lightly on a well-floured board. Roll it out until quite thin and cut biscuit shapes with a cutter of your choice.
Using a palette knife, lift the biscuits onto a well-buttered baking sheet.
Bake on the centre shelf of a moderate oven, Gas Mark 5, until pale golden in colour.
Remove from oven and sprinkle liberally with caster sugar while still warm.
Lift on to wire tray to cool and firm-up. Store in an airtight tin.