01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - In a large bowl, whisk together the flour, sugar, baking powder, baking soda, and salt until evenly distributed.
03 - Add the cold, cubed butter to the flour mixture. Cut the butter into the flour using a pastry cutter or your fingertips until the mixture resembles coarse crumbs.
04 - In a separate bowl, whisk together the cold heavy cream, egg, and vanilla extract until fully combined.
05 - Pour the wet ingredients into the flour mixture. Stir gently with a spatula until just combined. Do not overmix.
06 - Fold in the semisweet chocolate chips until evenly distributed throughout the dough.
07 - Turn the dough out onto a lightly floured surface. Gently pat into a 1-inch thick circle, approximately 7 inches in diameter.
08 - Cut the circle into 8 equal wedges using a sharp knife or bench scraper. Transfer wedges to the prepared baking sheet, spacing them 2 inches apart.
09 - Brush the tops of each scone with a thin layer of additional heavy cream for a golden, glossy finish.
10 - Bake for 16 to 18 minutes, or until the tops are golden brown and a toothpick inserted into the center comes out clean.
11 - Cool scones on the baking sheet for 5 minutes, then transfer to a wire rack. Serve warm or at room temperature.