In a large bowl, cream butter and confectioners' sugar until light and fluffy. Stir together flour and baking powder; blend into butter mixture. Pat into tart shells.
Bake in preheated oven for 12 to 15 minutes, or until edges are lightly browned.
Notes
FUN FACTS about SHORTBREAD
Shortbread is called short because of the traditional ratio of one part sugar to two parts butter that lends a high fat content to the dough. This yields a soft, buttery crumb that melts in your mouth, similar to short crust pastry. This ratio is also what makes shortbread so crave-worthy.
A Scottish biscuit through and through, shortbread is eaten on special occasions and hasn’t changed much from its original form in the Middle Ages. When you eat or bake traditional shortbread, you’re essentially enjoying the same buttery treats that the Scots did many centuries ago.
Today, shortbread is gifted to loved ones on the Scottish New Year’s celebration of Hogmanay. When the clock strikes midnight, people run onto the streets to visit friends’ and family’s homes for the first time in the new year. To wish the homeowner good luck, it’s customary to present them with a box of shortbread (and a bottle of liquor for good measure).