Preheat oven to 375 F

Combine the flour, baking powder, salt and sugar in a large bowl.

Cut the butter into small pieces, then cut in the flour, using a pastry cutter or your fingertips.

Stir in currants {or other add-ins}.

Mix the egg yolk with the milk, then pour the mixture into the dry ingredients. Stir the liquid into the dry, mixing just until the dough holds together without crumbling. 

For the dough into a disk {about 1 ½” thick” on a parchment lined baking sheet and brush the tops with the reserved egg white. 

Sprinkle it with sparkling sugar.

Cut the disk into 8 even wedges, then slightly separate the edges. 

Bake the scones for 15 – 18 minutes or until golden brown and baked through.