
In a large bowl, combine the flour, cocoa powder, sugars, baking powder, espresso powder, salt, baking soda, cinnamon, and chocolate chips.
Add the butter and cut with a pastry cutter or fork until the butter is the size of large peas.
In a separate bowl, whisk together the buttermilk, 1 egg, and vanilla extract.
Make a well in the middle of the dry mixture and add the liquid mixture. Mix until just combined. Don’t over-mix.
Transfer the dough to a floured surface. Shape dough into a rectangle. Fold the rectangle in half like a piece of paper. Flatten it out into a rectangle again. Fold in half once more, but in the opposite direction. This gently kneads the dough and stacks layers, making it cohesive and tall without overmixing.
Divide into 2 equal parts. Gently press each dough into a 1 ½-inch tall round. Using a bench scraper or knife, cut each round into 8 wedges and place onto parchment lined baking pans. Space them out about 2 inches apart.
Freeze for 1 hour before baking.
Adjust the oven rack to the center position and preheat to 400°F.
In a small bowl, whisk the remaining egg with 1 teaspoon of water. Brush over the chilled scones.
Bake for 18 to 20 minutes, or until the tops are set and firm. Let cool.
In a small bowl, combine the water and espresso powder until thoroughly dissolved. In a medium bowl, add the sugar. Pour the espresso mixture and cream/milk over the sugar and whisk until a thick glaze forms.
Drizzle each scone with glaze. Let set before serving.
The scones are best served the day they’re baked.