The best shortbread cookie recipe I have found. This was the 17th recipe I tried, and I’ve modified it slightly in order to consistently produce perfect cookies.
1½ cups salted butter, softened
1 cup confectioners sugar (icing sugar or powdered sugar)
3 cups all-purpose flour
Preheat oven to 325 F
Blend butter until smooth in a large bowl using an electric mixer set at medium speed. Slowly blend in the icing sugar. Scrape down the sides of the bowl and combine thoroughly. Add flour and mix at low speed until well blended.
Pat dough into an ungreased cookie sheet. Alternatively you can roll out the dough so that it's about ¼ of an inch in thickness and cut them to your desired shape.
Bake for 18 to 20 minutes, or until just done (slightly golden in color). Do not let the cookies get brown. Cut into squares if you haven't pre-cut them and place cookie sheet on wire rack to cool for 10 minutes.