Chef John'S Scones

Directions

1. 1
   Preheat oven to 400 degrees F (200 degrees C).
2. 2
   Whisk flour, white sugar, baking powder, and salt in a mixing bowl. Cut in butter with a knife or pastry blender until the mixture resembles coarse crumbs.
3. 3
   Stir together 1/2 cup milk, sour cream, and currants in a small bowl; stir into flour mixture with a fork until just moistened and holding together.
4. 4
   Transfer dough to a lightly floured surface and pat into rectangle.
5. 5
   Fold the rectangle in thirds. Turn dough a half turn, gather any crumbs, flatten back into a rectangle, and repeat. Cut into eight pieces and place each scone on a silicone baking mat.
6. 6
   Whisk egg and 1 tablespoon milk together in a small bowl; brush mixture on top of each scone.
7. 7
   Bake scones in the preheated oven until risen and golden brown, about 15 minutes. Remove and transfer to cooling rack.