Scottish Shortbread

Directions

1. 1
   [i]NOTE:If you don't have superfine sugar, make some by processing regular sugar in the food processor for about 30 seconds.
2. 2
   [/i]Oven to 300 degrees F.
3. 3
   Position the rack of your oven in the middle of the oven.
4. 4
   Line an 8x8 inch baking pan with heavy duty foil, letting it extend over the sides of the pan.
5. 5
   Sift the flour, cornstarch and salt together.
6. 6
   Pour into a food processor or your mixer along with the half-cup of sugar.
7. 7
   Mix briefly.
8. 8
   Add the butter and vanilla.
9. 9
   Mix or pulse the food processor several times just until the dough begins to come together- don't overprocess.
10. 10
    This will probably take 1-2 minutes.
11. 11
    Spread and gently press the dough into your pan.
12. 12
    Do not pack the dough down hard!
13. 13
    This is very important.
14. 14
    Just as gently as you can to get it evenly into the pan.
15. 15
    Bake the shortbread for about 1 hour 10 minutes, or until it just starts to turn golden.
16. 16
    If it doesn't look done, add another 10 minutes to the time.
17. 17
    When it comes out of the oven, sprinkle the remaining 2 tbl sugar over top.
18. 18
    Cut into 12 squares, then let cool completely before removing from the pan.