1cup(227 grams) unsalted butterlightly softened at room temperature (about 1 hour), plus more for greasing the pan
1/2cup(100 grams) caster (superfine) sugarplus more for topping
2 1/4cups(280 grams) all-purpose flour
1/2teaspoonssalt
Instructions
Preheat oven to 325˚F (160˚C). Grease an 8 x 8 inch (20 x 20 centimeter) square baking dish with butter.
In the bowl of a stand mixer fitted with a paddle attachment or a large bowl with a wooden spoon, mix together the butter and sugar until evenly combined, but do not cream completely together.
Mix in the flour and sugar just until the dough comes together and is no longer crumbly.
Gently press the dough into the greased pan in an even layer.
Cut the dough into individual rectangles about 2 1/2 x 1 inches (6 x 2.5 centimeters). Pierce the tops all over with a fork at least halfway through the dough.
Bake in the preheated oven until edges are lightly golden and the center is set, about 30-40 minutes.
Immediately after removing from the oven, sprinkle sugar lightly across the top of the shortbread.
Allow to cool briefly in the pan for about 5 minutes, then cut across the lines again to separate the shortbread into individual pieces while still warm.
Once cooled, store at room temperature in airtight container for up to a week.