Set your oven rack on a rung in the top third of the oven. Preheat the oven to 425°F. Lightly grease a baking sheet, or line it with parchment paper., Weigh your flour; or measure it by gently spooning it into a cup, then sweeping off any excess. In a medium bowl whisk together the flour, baking powder, baking soda, salt, and ground dry spices., Add the cold butter, tossing to coat with the dry ingredients. Then press the butter pieces between your thumbs and forefingers into small flat pieces, or "leaves.", Add the ginger and toss to combine., In a small bowl whisk together the cream and brown sugar., Add the wet ingredients to the dry ingredients and mix gently until the mixture is just combined. The dough should be firm and barely cohesive (some dry bits are OK)., Transfer the dough to a lightly floured work surface, and fold a few times to incorporate any dry bits if necessary., Pat the dough into a circle 1" thick and 7" across. You may chill the dough until set for easier cutting., Cut the dough into eight wedges with a chef's knife, cutting directly down; don't saw. Arrange the scones evenly on the prepared pan., Brush the scones with the egg wash and garnish with coarse sugar., Bake the scones for 18 to 22 minutes on the top rack, rotating after 14 minutes, until they're light gold and firm to the touch., Remove the scones from the oven, and serve warm or at room temperature. Store baked scones, well wrapped, at room temperature for 2 to 3 days; or freeze for up to 1 month.