Best ever Scottish shortbread

Directions

1. 1
   Line a baking tray with parchment and turn the oven on to gas mark 3 low.
2. 2
   Add the plain flour and chopped butter to a large mixing bowl.
3. 3
   Rub the butter into the flour until it resembles fine breadcrumbs.
4. 4
   Add the caster sugar and carry on rubbing in until thoroughly dispersed in the mixture.
5. 5
   When the mixture starts to stick together, knead until it forms a nice pliable dough.
6. 6
   Knead into a square block.
7. 7
   Shape into a square slab on a chopping board.
8. 8
   If following my quantities as listed above, cut the slab into four, but if doubling the ingredients enough to make 64 biscuits shape into a rectangle and cut into eight pieces as shown in the picture here.
9. 9
   Take each piece in turn and roll into a sausage shape.
10. 10
    Cut with a sharp knife into eight circles.
11. 11
    Place each biscuit carefully onto the baking tray spaced to allow for spreading during cooking.
12. 12
    Prick each biscuit three times with a fork.
13. 13
    Place on the middle shelf of the oven on a low setting and cook the biscuits for about 35 to 40 minutes.
14. 14
    Do not let them get too dark in color, they should be a very pale color when done.
15. 15
    Take out of the oven and leave to cool down a bit before taking them off the tray as they will be too soft and break.
16. 16
    Cool them on a wire rack.
17. 17
    When cooled dip each shortbread biscuit into a bowl of caster sugar and shake off the excess sugar.
18. 18
    These biscuits store well in a tin.
19. 19
    Enjoy!