01 - Preheat the oven to 400°F. Line a baking sheet with parchment paper.
02 - In a large bowl, whisk together flour, sugar, baking powder, baking soda, salt, and lemon zest until well combined.
03 - Add the cold butter to the flour mixture. Cut it in using a pastry cutter or your fingers until the mixture resembles coarse crumbs.
04 - In a small bowl, whisk together the cream, egg, and vanilla extract until smooth.
05 - Add the wet ingredients to the dry mixture. Stir gently just until combined. Do not overmix.
06 - Gently fold in the blueberries until evenly distributed throughout the dough.
07 - Turn the dough onto a lightly floured surface. Pat into a 7–8 inch circle, about 1 inch thick.
08 - Cut the dough circle into 8 wedges. Transfer to the prepared baking sheet, spacing slightly apart.
09 - Brush the tops of the scones with a little extra cream for a golden finish.
10 - Bake for 18–22 minutes, or until golden brown and cooked through. Cool on a wire rack.
11 - While scones cool, whisk together powdered sugar, milk, and vanilla for the glaze until smooth and pourable.
12 - Drizzle glaze over cooled scones before serving.