• Preheat oven to 400°F and move rack to the center.
• Begin by whisking the flour, sugar, cinnamon, allspice, and baking powder together in a large bowl.  
• Cut the cold butter into cubes and then add it to the dry ingredients. Use a pastry blender or two knives to cut the butter into the dry ingredients until it resembles coarse crumbs.  The butter should be no larger than the size of a pea. 
• Make a well in the center of the flour mixture, then pour the eggnog and vanilla into the well.
• Fold the dry ingredients into the wet and gently stir until the dough forms into a loose ball.  You should have a slightly sticky dough that should not feel wet. 

  If the dough feels too wet add a tablespoon of flour at a time until it is just slightly sticky, if it is too dry then add a tablespoon of eggnog at a time until it is the right consistency.
• Turn the dough onto a lightly floured counter or pastry mat, then form it into a ball. Gently press it out into a circle approximately 8 inches in diameter.
• Using a sharp knife, cut the circle into eight wedges.  Transfer the wedges to a baking sheet lined with parchment paper.
• Brush the tops with one to two tablespoons of eggnog.
• Bake the scones for 18-22 minutes until they have risen and are slightly golden brown.
• Remove from the oven and cool for at least 10 minutes before adding the drizzle. 

Icing the Scones

• Mix the powdered sugar with the eggnog and stir until it is your desired consistency. If you like thick icing, add a bit more powdered sugar; if you prefer a thinner drizzle, add more eggnog.
• Ice the scones by drizzling the icing over the top, or for thicker frosting, you can spread it with a spatula, knife, or use a pastry bag to pipe it on. If desired, grate a bit of fresh nutmeg on the scones while the icing is still sticky.