Directions
Preheat the oven to 400°F. Line a baking sheet with parchment paper. To make the scones, in a large bowl, whisk together the flour, baking powder, sugar, and salt until combined. Add the chopped chocolate and stir until mixed. With a pastry blender, cut in the butter.

In a small bowl, stir the heavy cream and egg yolks until slightly blended. Add to the flour mixture and stir with a spoon until the dough just starts to come together. Use your hands to knead the mixture until the dough can be gathered into a moist ball. Do not overknead—the stickiness of the dough is good. Set the ball on the prepared baking sheet and flatten it to form a round about 8 inches in diameter and 1 inch thick. With a sharp knife, cut the dough into eight wedges (like cutting pieces of a pie), and separate the wedges on the baking sheet about 2 inches apart.

To make the glaze, lightly beat the egg and milk. Using a pastry brush, brush the tops of each scone with the egg and milk mixture and sprinkle with sugar. Bake the scones for 18 to 20 minutes, until a tester inserted into the center of a scone comes out clean. Transfer the scones still on the parchment paper onto a wire rack and let cool before serving, about 15 minutes. These can be stored for 2 to 3 days.