(from Karen)
2 cups (280 grams) all purpose flour
1/4 cup (50 grams) granulated white sugar
1 teaspoon baking powder
1/4 teaspoon baking soda
1/4 teaspoon salt
1/2 cup (113 grams) (1 stick) unsalted butter, cold and cut into pieces
2/3 cup (160 ml) buttermilk
1 large egg, lightly beaten
1 tablespoon milk
Preheat oven to 400 degrees F and place rack in middle of oven. Stack two baking sheets together and line the top baking sheet with parchment paper. (This prevents the bottoms of the scones from over browning during baking.)
Transfer to a lightly floured surface and knead dough gently four or five times and then pat, or roll, the dough into a circle that is about 7 inches (18 cm) round and about 11/2 inches (3.75 cm) thick. Cut this circle in half, then cut each half into 3 pie-shaped wedges (triangles).
Place the scones on the baking sheet. Make an egg wash of one well-beaten egg mixed with 1 tablespoon milk and brush the tops of the scones with this mixture.
Bake for about 15 to 20 minutes or until golden brown and a toothpick inserted in the middle comes out clean. Remove from oven and then turn your broiler on high.