01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - In a large bowl, whisk together flour, sugar, baking powder, salt, and lemon zest.
03 - Add cold, cubed butter and cut into dry ingredients using a pastry cutter or fingertips until mixture resembles coarse crumbs.
04 - In a small bowl, whisk heavy cream, egg, and vanilla extract until combined.
05 - Pour wet ingredients over dry and mix gently until just combined.
06 - Carefully fold in blueberries, avoiding overmixing to maintain berry integrity.
07 - Turn dough onto lightly floured surface and pat into a 1-inch thick circle.
08 - Cut dough into 8 wedges and transfer to prepared baking sheet, spacing slightly apart.
09 - Lightly brush tops with additional heavy cream.
10 - Bake for 18 to 22 minutes until golden and cooked through; then cool on a wire rack.
11 - Whisk confectioners sugar, milk or cream, and vanilla extract until smooth.
12 - Drizzle glaze over cooled scones before serving.