Ingredients
- 1 cup unsalted butter , plus softened
- 2 tablespoons unsalted butter , softened
- 1/2 teaspoon salt
- 1 3/4 cups all-purpose flour , plus
- 2 tablespoons all-purpose flour
- 1/2 cup cornstarch , plus
- 2 tablespoons cornstarch
- 1/3 cup sugar
- 1/4 cup superfine sugar or 1/4 cup granulated sugar , for topping
Directions
-
Preheat oven to 325°; butter a 10×6 inch glass baking dish.
-
Add butter to a mixing bowl—the butter must be very soft, the consistency of mayonnaise or whipped cream.
-
Add the salt to the butter and mix well with a wooden spoon or whisk sot that it dissolves completely before you add the rest of the ingredients.
-
Sift the flour and cornstarch together into a bowl.
-
Add the sugar to the butter and mix just until combined.
-
Add the flour mixture and mix just until a smooth dough forms.
-
Pat the dough evenly into the prepared baking dish; the dough should be no more than 2/3 inch deep.
-
Bake until the top and bottom are lightly browned, about 30 minutes.
-
The middle of the shortbread should remain light; let cool on a wire rack until warm to touch.
-
Sprinkle the shortbread with the superfine sugar; tilt the dish so that the sugar fully and evenly coats the surface and then tip out the excess sugar.
-
With a very thin, sharp knife, cut the shortbread into rectangular fingers, about ½ inch wide and 2 inches long; if the cookies have become cold, they will not slice well, so they must still be warm to the touch at this point.
-
Chill thoroughly before removing from the baking dish; the first cookie is difficult to remove, but the rest should come out easily with the aid of a small, thin offset spatula.