Preparation

1. Preheat the oven to 425°F. Line two baking sheets with parchment paper. Reserve.
2. Insert the shredding disc in the food processor. Shred the Gruyère. Remove and reserve.
3. Replace the shredding disc with the metal chopping blade. With the unit running, drop the scallions through the feed tube and process until chopped.
4. Scrape down the sides of the bowl and then add the flour, baking powder, and salt. Process to sift, about 10 seconds. Add the butter and pulse until small pieces form and they are coated with flour. Combine the heavy cream and the egg into a liquid measuring cup and whisk to combine. While pulsing, add the heavy cream/egg mixture through the feed tube. Pulse until very few dry bits of flour are visible. The dough will be shaggy and sticky.
5. Turn the dough onto a lightly floured surface and lightly dust the top of the dough with additional flour.
6. With floured hands, gently form the dough into a ½-inch-thick 11×6-inch rectangle. Sprinkle the crumbled bacon over top and then fold one-third of the dough toward the center, and then the opposite side folded over that (like folding a letter to put into an envelope).
7. With gentle hands, form the dough into a log 16 inches long. Using a knife or bench scraper, cut into 8 pieces. Place the scones 1 inch apart on the reserved baking sheets.
8. Lightly brush the top of each scone with the egg wash and sprinkle evenly with the shredded Gruyère.
9. Bake for about 15 minutes, rotating the pan halfway through, until the tops are golden brown. Serve warm.