As I was born in Scotland, great shortbread has always been a Christmas tradition in our family. A few years ago I started to experiment with my great grandmother's recipe, to make it quicker and easier to make. I successfully managed to change the ingredients and the method to make it tastier and fast to make. It's now a family tradition (and expectation) that ALL our family members receive a small gift box of my shortbread at Christmas.
Preheat oven to 150 degrees C – fan forced; 170 degrees C otherwise. Place the butter and sugar in a mixer or food processor and cream until pale.
Once well mixed, add the flours and blend briefly, just until thoroughly combined.
Tip into a buttered Swiss-roll tin (23x33cm) and, using lightly floured hands, press down so it is level all over.
Prick all over with a fork. Do this carefully, so that you do not disturb the level surface, then bake at 150C (fan forced) for 50-60 minutes. What you are looking for is a uniform pale golden colour all over. Do not allow it to become too dark.
Remove from oven and cut into squares or fingers in the tin, sprinkle the top with caster sugar. Leave for 5 minutes or so then carefully turn out onto a wire rack, and allow it to cool. Store in air tight container.