Preheat your oven to 400°F (200°C).
In a large bowl, whisk together the flour, granulated sugar, baking powder, and salt.
Cut in cold butter until the mixture resembles coarse crumbs.
In a separate bowl, whisk together the milk, egg, and ground cinnamon.
Pour the wet ingredients into the dry mixture and stir until just combined.
Turn the dough out onto a floured surface and gently knead it a few times.
Pat the dough into a 1-inch thick circle and cut into wedges.
Place the scones on a parchment-lined baking sheet and brush tops with milk.
Mix together the extra sugar and cinnamon, then sprinkle on top of the scones.
Bake for 15-20 minutes, or until golden brown.
Allow the scones to cool slightly before serving.
