In a large bowl, stir together flour, baking powder, baking soda, sugar and salt.
Cut in cold butter until the mixture resembles coarse crumbs.
In a small bowl, beat egg with buttermilk; add to flour mixture folding just until mixture clings together (the key to a tender scone is to avoid over mixing the dough).
Turn dough out onto a floured board and with floured hands pat into a 12-inch circle.
Spread with the 3 tablespoons of softened butter.
Mix brown sugar with cinnamon and sprinkle all over the butter.
Roll dough from the outer edge (all the way around) towards the middle (you will end up with a ball of dough).
Turn dough over on the floured board and pat into an approx 8-inch circle that is about an inch thick.
With a large sharp knife, cut into 6 – 8 wedges.
Place in a square baking pan or cookie sheet
Brush with milk and sprinkle with lots of cinnamon sugar.