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, salt, and lemon zest until evenly mixed.
03 - Add cold butter cubes to dry ingredients. Use a pastry cutter or fingertips to incorporate butter until mixture resembles coarse crumbs with some pea-sized pieces.
04 - In a separate bowl, whisk heavy cream, egg, vanilla extract, and lemon juice until smooth.
05 - Pour wet ingredients into dry mixture. Stir gently until just combined, avoiding overmixing.
06 - Carefully fold fresh or frozen (unthawed) blueberries into the dough.
07 - Turn dough onto a lightly floured surface. Pat into a 7-inch diameter round approximately 1 inch thick.
08 - Cut dough into 8 evenly sized wedges. Arrange wedges on the prepared baking sheet, spaced apart.
09 - Lightly brush the tops of wedges with additional heavy cream.
10 - Bake scones for 16 to 18 minutes until golden and fully cooked. Transfer to a wire rack to cool.
11 - Whisk powdered sugar, lemon juice, and grated lemon zest until smooth and slightly runny. Drizzle glaze over cooled scones.