Preheat oven to 375 F. Line your baking sheets with parchment paper. Place the flour, baking powder, salt and 1/3 cup sugar in a large mixing bowl. Stir to mix everything. Add in the pieces of cold butter. Use your hands to rub the butter into the flour until you get coarse crumbs type mixture. Make a well in the middle of the bowl. Crack in egg and pour in buttermilk. You may use your clean hands or spoon to mix the egg with the milk and then slowly mix the flour in. The dough will be at the wet and sticky side (Please DON'T BE ALARMED!)

Dust your hands with some powdered sugar and dust your working surface with some powdered sugar. I don't want to dust with flour because all that does is making the scones tougher and drier. Work the dough until you get a smooth surface, but it will still be a little wet. Wash your hands and then rub some cooking oil on both palms. Divide the dough into 4 equal sizes. Shape them into balls. Pick up on dough and flatten into about 4 to 5-inch disc, about 1/2-inch in thickness (make sure your hands are still nicely greased at this point). Repeat with the rest of the dough

Working with one flattened dough at a time, sprinkle with about 1/2 cup of cheese on the dough, leaving about 1/2-1 inch around the edge. Top evenly with half of the corned beef hash and then sprinkle with another 1/2 cup of cheese. Try to spread the filling out evenly. Gently pick up another flattened dough and place on top of the cheese. Seal the edge and use your hand to lightly pat around the edge to give you a roughly smooth round. Repeat with the other two doughs. You will get two large scones. Brush the top of the scones with some buttermilk and then sprinkle with some sugar on top

Place them into the oven and bake for the next 20-35 minutes. It takes about 35 minutes on mine to get them to be nicely golden brown. So, watch your oven, you may not need that long

Once they are golden brown, pull them out from the oven and let them rest for 10 minutes before slicing. I recommend slicing them only when you ready to serve them. It helps to keep the inside moist. You can always wrap them in aluminum foil to keep it warm and then slice them later. They are best served when warm