Mix the flour and sugar together in a large bowl, and then rub in the butter - as if you were making shortcrust pastry. Use the tips of your fingers and ensure that all the butter has been rubbed in -- it should resemble sand!
2. Then start to knead the paste, pushing it together to form a smooth dough - the heat of your hands whilst kneading helps it form.
9. Roll out the shortbread dough, and shape into a rectangle, about 1/2" to 3/4" thick. Place onto a well greased baking tray or cookie sheet as before, and mark into "fingers" -- prick over with a fork again. You can also press the dough into an 8" square baking/sandwich/brownie tin - and then mark out the fingers as above.10. (Please Note: The fingers are always thicker than the petticoat tails and shortbread
11. Bake the any of the above shortbread biscuits in a pre-heated oven 150C for between 30 to 40 minutes, or until they are pale and golden - but NOT brown!12. Sprinkle extra caster sugar over the top as soon as they come out of the oven if you wish.13. Allow the shorbread bicuits to cool slightly on a cooling rack, before cutting into fingers or "petticoat tails".
14. Allow to cool completely before storing in an airtight tin or container. NB: These will last for about 10 to 14 days in a cool, dry and dark pantry. They can also be frozen with great results!