Whisk flour, cocoa powder, sugar, baking powder, cinnamon, and salt together in a large bowl. Grate the frozen butter using a box grater. Add it to the flour mixture and combine with a pastry cutter, two forks, or your fingers until the mixture comes together in pea-sized crumbs. Place in the refrigerator or freezer as you mix the wet ingredients together.

Whisk heavy cream, egg, and vanilla extract together in a small bowl. Drizzle over the flour mixture, add the 6 ounces of chopped chocolate, then mix together until everything appears moistened.

Pour onto the counter and, with floured hands, work dough into a ball as best you can. Dough will be sticky. If it’s too sticky, add a little more flour. If it seems too dry, add 1-2 more Tablespoons heavy cream. Press into an 8-inch disc and, with a sharp knife or bench scraper, cut into 8 wedges.

Place scones on a plate or lined baking sheet (if your fridge has space!) and refrigerate for at least 15 minutes.

Meanwhile, preheat oven to 400°F (204°C).

Line a large baking sheet with parchment paper or silicone baking mat. After refrigerating, arrange scones 2-3 inches apart on the prepared baking sheet(s).

Bake for 22-25 minutes or until edges and top are set. Chocolate scones are done when a toothpick inserted into the center comes out clean. Remove from the oven and cool for a few minutes as you prepare the glaze.

Make the glaze: Whisk the confectioners’ sugar, vanilla, and water together. Dunk warm scones into the glaze and place on a wire rack with a baking sheet or paper towels underneath to catch the glaze as it drips down. The glaze will set after several minutes, but you can serve right away. Before serving, melt the 4 ounces of semi-sweet chocolate in the microwave in 15 second increments, stirring after each increment until melted. Drizzle over scones.

Leftover glazed or un-glazed scones keep well at room temperature for 2 days or in the refrigerator for 5 days.