Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
In a large mixing bowl, whisk together the flour, sugar, baking powder, and salt until well combined.
Add the cold, cubed butter to the flour mixture. Using a pastry cutter or your fingers, work the butter into the mixture until it resembles coarse crumbs.
Gently fold in the fresh blueberries and lemon zest, ensuring they are evenly distributed throughout the dough.
In a separate bowl, whisk together the buttermilk, egg, vanilla extract, and lemon juice until combined.
Pour the buttermilk mixture into the flour mixture and stir until just combined. Be careful not to over-mix; the dough should be slightly sticky.
Turn the dough out onto a floured surface and shape it into a 1-inch thick circle. Cut the dough into 8 wedges or use a round cutter for individual scones.
Place the scones on the prepared baking sheet. Brush the tops with a little buttermilk and sprinkle with coarse sugar for added sweetness and crunch.
Bake in the preheated oven for 15-20 minutes, or until the scones are golden brown and a toothpick inserted comes out clean.
Remove from the oven and allow to cool slightly on a rack before serving.
Notes
Serve warm, dusted with powdered sugar, and with lemon curd or clotted cream.