2 cups of all-purpose flour
2 tbsp sugar
1 tbsp baking powder
½ tsp baking soda
½ tsp salt
3 tbsp cold butter, cut into ¼-inch chunks
¾ cup milk
1 egg, separated
Sift together the dry ingredients. Cut in the butter with a pastry blender or two butter knives until the mixture resembles coarse crumbs. In a separate bowl, whisk the milk and egg white. Pour over the dry ingredients and stir very gently, just until moistened.
Turn dough, which will be quite sticky, onto a lightly floured surface. Dust with more flour and add some flour to your hands, and knead gently 5-10 times. Pat into a 10-inch circle or, for smaller scones, into two five-inch circles. Cut into wedges.
Bake on a pan lined with parchment paper at 350 degrees F until golden brown, about 25 minutes. Serve with jam and Devonshire cream.