Preheat the oven to 375 ºF. Line a baking sheet with parchment paper.
Whisk together the half-and-half and egg in a small bowl. Mix together 2 tablespoons of the sugar and the cinnamon in another small bowl.
Mix together the flour, remaining sugar, the zest, ginger, baking powder, baking soda, cloves and salt with a whisk in a large bowl. Work the butter into the dry mix by crumbling everything with your fingertips or cutting it into the mix with a pastry cutter, until the butter is in small bits. Working quickly, add the buttermilk and mix with a wooden spoon until the dough comes together.
Turn the dough out onto a floured surface and press the dough together into a ball. Cut the dough into 2 pieces, one larger than the other, about one-third to two-thirds. Roll each piece of dough into a 12- by 9-inch rectangle. Spread the jam on the thicker rectangle of dough and top with the blueberries. Place the thinner rectangle of dough on top of the blueberry layer. Brush the egg wash on top of the dough and sprinkle with the cinnamon-sugar mixture.
Cut the dough into 18 equal pieces, about 3 by 2 inches using a bench scraper. Place the scones on the baking sheet and bake in the middle of the oven until the tops of the scones are just firm to the touch, 20 to 25 minutes. Cool for 1 minute, and then transfer to a cooling rack. Let cool for at least 5 minutes.
