Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.
In a large bowl, whisk together the flour, cocoa powder, sugar, baking powder, and salt.
Cut in the cold butter using a pastry cutter or your fingers until the mixture resembles coarse crumbs.
Stir in the chocolate chips.
In a separate bowl, whisk together the heavy cream, egg, and vanilla extract.
Pour the wet ingredients into the dry ingredients and mix until just combined.
Turn the dough out onto a lightly floured surface and knead gently a few times until it comes together.
Pat the dough into a circle about 1 inch thick. Cut into 8 wedges and place them on the prepared baking sheet.
Bake for 18-20 minutes, or until the scones are set and a toothpick inserted into the center comes out clean.
Let cool on a wire rack before serving.