Shortbread Fingers

I did not actually make these Shortbread Fingers. So I can not take credit for them. However, they tasted so good that I could not resist posting them. My little sister Andrea made these from Martha Stewart's Baking Handbook. Enjoy!


Ingredients
3 sticks unsalted butter, room temperature, plus more for pan
2 1/2 cups all-purpose flour
1/4 teaspoon salt
3/4 cup plus 2 tablespoons confectioners' sugar
Granulated sugar, for sprinkling

Directions:
1) Preheat the oven to 325 F. Butter a 12-by-8-inch rimmed baing sheet and line with parchment paper, leaving a 1-inch overhang on long sides. Whisk together flour and salt in a small bowl; set aside.
2) In the bowl of an electric mixer fitted with the paddle attachment, beat butter until fluffy on medium speed, 3 to 4 minutes. Add confectioners' sugar; continue to beat until very light and fluffy, about 2 minutes, scraping down the sides occasionally, until just incorporated. (It should have the consistency of soft cookie dough.)
3) Using a small offset spatula, evenly spread dough in prepared baking sheet. Chill in the freezer or refrigerator until dough is firm, about 15 minutes.
4) Prick dough all over with a fork. Bake, rotating sheet halfway through, until shortbread is golden brown, 40 to 45 minutes. Transfer to a wire rack and immediately sprinkle with granulated sugar. While still hot, use a large knife to cut shortbread into 4-by-1 inch pieces. Cool completely in the pan. Shortbread can be kept in an airtight container at room temperature for up to 1 week.