Serve with Lemon Curd, as an accompaniment to another dessert, crumbled in trifles or cruts for pies or cheesecakes or on its own. The Classic Scottish Shortbread needs no adornment, but a drizzle of chocolate never hurt!
Preheat oven to 325 degrees F.
If making by hand:
Add flour and sugar to a large bowl and mix. Add butter(along with salt and/or extract if using). Using hands, a pastry cutter or two knives, break butter down into very small crumb-like pieces. Working with fingers, continue to mix and knead together until a dough forms and the majority of the crumbs are incorporated. Some crumbs are fine. Keep at it and it will come together.
If making in food processor:
Work with half of dough at a time. Measure half of the flour and sugar into a food processor fitted with a blade attachment and pulse several times. Add half the butter (along with 1/2 of salt and/or extract if using) and pulse briefly three or four times to coat butter with flour. Continue to pulse in 8 second increments until the mixture begins to clump together. Remove to a large bowl. Repeat with remaining ingredients.
After both halves are combined, continue to work with hands until the majority of the crumbs are incorporated.
For both methods:
Spread dough onto a rimmed cookie sheet, 15x10x1″, breaking up dough clumps if necessary. To get as even as possible (it won’t and shouldn’t be perfect) use a butter wrapper or piece of lightly oiled parchment between your hand or the bottom of a glass or other utensil to lightly even and flatten the shortbread.
Dock about 1 1/2 inches apart in rows. A larger serving fork works well for this.
Place in oven and bake for 20 to 25 minutes until the shortbread has turned a very light golden color. Watch the edges and remove when edges pick up just a hint of golden brown color. The shortbread will be very pale.
Cut into bars while still warm. Most traditional bars are rectangles, longer than they are wide.
Measure flour by stirring to lighten then gently spoon into measuring cup and level off.
Butter should be very cold. Cut into chunks, quartering each butter quarter the long way, then cutting across into 1/2″ pieces. If using food processor method, divide butter into two before cutting. If time allows, place in freezer for 10 minutes before continuing with the recipe. Save a wrapper to smooth the dough.
Shortbread will be softer and more crumbly when first baked, but will crisp more after it cools completely and sits for awhile.