combine the dry ingredients: flour, baking powder, salt and sugar. Cut the cold butter into cubes and with your hands incorporate all of the butter. Shake the bowl to bring up the larger lumps. Bring the flour-butter mixture up in your hands and rub your hands back and forth to aid in incorporating the butter - you want a complete breadcrumb texture. Make a well in the center of the flour/butter mixture. Whisk the egg and combine with the buttermilk. Pour into the well and gently stir together. Add additional buttermilk until the dough just forms a soft ball - the texture should be similar to soft play dough. Add the raisins. Cover and let rest for 15 to 20 minutes. Lightly flour the board or surface, turn over the dough onto the flour; flour your hands and press down forming a disk. You can roll out the dough as you wish - to about 1/2 to 3/4 inches in depth. Dip your cutter into the flour; tap off the excess and cut lifting directly up; place the scone on a prepared baking sheet (I like using parchment paper) continue and work until you've used all or nearly all of the dough - prepare the egg wash by mixing the egg and milk thoroughly. Lightly brush on the tops of the scone the egg wash. Bake at 400 degrees for 10 to 15 minutes until golden brown. Serve hot.