NOTE: If you don't own a food processor, make these scones as you would make biscuits!
In a food processor combine all of the dry ingredients, give a whirl to mix. With the food processor running, add pieces of butter, a couple at a time, and pulse until pea sized. Continue adding the butter until you use all of it.
Add the heavy cream. Pulse until the dough comes together.
Add the ginger and cranberries, and give a quick pulse.
Remove the dough from the food processor, and knead on a lightly floured counter top. Pat into a circle, about 3/4 inch thick. Cut into 8-10 triangles.
Place onto a baking sheet, with space between each one.
Make an egg wash with the egg and a tablespoon of water. Using a pastry brush, lightly brush the tops of the scones with the egg wash, and sprinkle a little sugar on each top.
Bake for 15 – 20 minutes, until the scones are golden brown on the tops. Remove from the oven. Let cool for 5 minutes.