Step 1

Position a rack in the middle of the oven and preheat the oven to 375°F (190°C). Line a rimmed baking sheet with parchment.

Step 2

In a large mixing bowl, combine both flours, the baking powder, baking soda, salt, sugar, and pepper and whisk until completely blended.

Step 3

Add the butter and, working quickly so that the butter doesn’t become warm, cut it in with a pastry blender. You should have various-sized pieces of butter ranging from coarse sandy patches to flat shaggy pieces to pea-sized chunks, with some larger bits as well. Add the bacon and cheese and toss to distribute evenly.

Step 4

Gradually pour in the buttermilk and gently fold the ingredients together until you have a soft dough with no bits of flour on the bottom of the bowl. If the dough seems dry, you may need to add a little more buttermilk. You should still see bits of butter in the dough; these will give you light and flaky scones.The dough will be moist and slightly sticky.

Step 5

Turn the dough out onto a lightly floured surface and roll or pat it into a 12-inch (30 cm) square about 1 1/2 inches (4 cm) thick. Cut into 12 squares and arrange about 2 inches (5 cm) apart on the prepared baking sheet, so the scones have room to puff up and rise. Brush the tops of the scones liberally with the egg wash.

Step 6

Bake, rotating the baking sheet halfway through for even baking, until the scones are lightly golden brown, 30 to 35 minutes.

Step 7

Cool the scones on a wire rack for about 10 minutes, then serve warm or at room temperature. The scones are best eaten the day they are made.