I lied (a tiny bit) in the title. This receipt has nothing to do with the Livingston Family; there is absolutely no evidence that it is of Scottish origin; and it is good anytime, not just at Christmas. 

     It appeared originally in a small, "local" cookbook entitled "Country Kitchen Classics" printed by the Highway Book Shop of Cobalt, Ontario, Canada. 
 
 

• 4 cups cake and pastry flour
• 6 Tbsp rice flour
• 1 cup white sugar, finely granulated
• 1 pound soft butter
• 1 tsp vanilla extract
• 2 egg yolks
• ½ tsp salt

• If the butter is hard, soften slightly by microwaving for a minute or so at 50%.

• Cream butter with an electric mixer until smooth and soft. Add sugar. Add egg yolks. Beat well. Add vanilla and salt. Add 6 Tbsp rice flour and gradually add pastry flour 1 cup at a time.

• Put the dough on a big cookie sheet and pat into two big disks, about 9 inches in diameter. Try using a 9 inch cake tin as a big cookie cutter to get it nice and neat. Cut each disk into twelve triangular slices and sprinkle with coarse red and green sugar. Pat slightly to make sure the sugar sticks.

• Bake at 280ºF for an hour. Cut again immediately after removing from the oven. Allow to cool for ½ hour before loosening with a spatula. 

• If you have trouble with cookies sometimes going brown on the bottom, try using the "top" oven rack in the middle of the oven with another cookie sheet on the lower rack as a "heat shield" between the element and the actual cookie sheet.

• Take care not to overcook or the butter starts to brown resulting in a less tender product with a less buttery flavour. The shortbread should be a very, very pale gold colour when removed from the oven, and it seems to darken slightly as it cools.