Preheat the oven to 140C/275F/Gas mark 1
Cream the butter until soft. Gradually add the brown sugar, creaming after each addition until light and fluffy. Add the flour gradually. Knead the dough on a lightly floured board for 10-15 minutes. Roll out dough to ½ inch thick and cut with floured biscuit cutters. Transfer to an ungreased baking tin. Bake for 30 minutes until lightly browned around the edges and with a firm centre. Cool, store in airtight container, with layers separated by napkins.