Preheat the oven to 204C /400F.
Line a baking sheet with parchment paper (you may need 2 trays).
In a mixing bowl, combine together flour, sugar, baking powder, and salt.
Add the grated butter and combine until the mixture looks like coarse crumbs. Then add the Parmesan cheese and 3 tablespoons of the chopped rosemary.
Next, mix in the egg and buttermilk until just combined, being careful not to over mix the dough. Then gently fold in the Parma ham.
Turn the dough out onto a floured surface and then pat into a 1-inch thick square.
Cut the dough into 8 wedges, then lightly press remaining tablespoon of rosemary on top of wedges.
Place scones about 2 inches apart on the already prepared baking sheets, and brush with remaining buttermilk.
Place the preheated oven and bake for 16-18 minutes, or until the scones are golden brown and a skewer inserted in the middle comes out clean.
Allow the scones to cool for a couple of minutes, then serve warm.