2 1/2 cups all purpose flour
1 cup butter - room temperature
3/4 cup sugar
extra sugar to sprinkle on top
Preheat oven to 300 degrees (150 degrees C)
Mix flour and sugar together, add butter and mix to a fine breadcrumb texture, press dough into a lined greased pan 13 X 9 (I used a pyrex dish).
Sprinkle with extra sugar.
Bake in the oven until the edges are light brown (20 to 30 minutes, all ovens vary).
Cut shortbread into squares while still in the pan and warm (I use a pizza cutter). Lift out of the pan by the lining when cooled.