01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - In a large bowl, whisk together flour, sugar, baking powder, baking soda, and salt until well combined.
03 - Add cold butter cubes to the flour mixture. Using a pastry cutter or your fingers, cut butter into flour until mixture resembles coarse crumbs.
04 - Stir the chocolate chips into the flour-butter mixture until evenly distributed.
05 - In a separate bowl, whisk together heavy cream, egg, and vanilla extract until combined.
06 - Pour wet ingredients into dry ingredients. Gently mix with a fork until just combined. Do not overmix.
07 - Turn dough onto lightly floured surface. Pat into a 1-inch thick circle. Cut into 8 wedges and transfer to prepared baking sheet.
08 - Brush tops with additional cream. Bake for 16-18 minutes until golden brown. Cool on wire rack.
09 - Whisk powdered sugar, milk (start with 2 tablespoons), and vanilla until smooth. Adjust consistency with additional milk if needed.
10 - Drizzle glaze over cooled scones. Allow glaze to set before serving.