There's nothing more Christmasy than shortbread. For years I tried to make this delicate, buttery treat, but I could never get it quite right. My shortbread was crumbly and dense and tasted of defeat, which is rather salty on account of all the tears in the batter. A couple years ago a friend of mine heard me ranting about how shortbread was the bane of my holiday existence. She decided to bestow a Christmas miracle on me in the form of these easy, no fail shortbread cookies. She is a …