Preheat your oven to 400°F (200°C).
In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, light brown sugar, baking powder, baking soda, and salt until well combined.
Add the cold butter pieces to the dry ingredients. Using a pastry cutter or your fingers, cut the butter into the flour mixture until it resembles coarse crumbs.
In a separate bowl, whisk together the cold heavy cream, large egg, and vanilla extract until well blended.
Pour the wet ingredients into the dry ingredients and stir gently with a spatula until just combined. Be careful not to overmix; the dough should be slightly crumbly.
Fold in the chocolate chips, ensuring they are evenly distributed throughout the dough.
Turn the dough out onto a lightly floured surface. Gently knead the dough a few times until it holds together, then pat it into a circle about 1-inch thick. Cut the circle into wedges or use a biscuit cutter for round scones.
Place the scone pieces on a baking sheet lined with parchment paper. Brush the tops with the additional heavy cream and sprinkle with turbinado sugar for a crunchy finish.
Bake in the preheated oven for 15-20 minutes, or until the scones are golden brown and a toothpick inserted into the center comes out clean.
Allow the scones to cool on a wire rack for a few minutes before serving.