01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - Whisk together flour, sugar, baking powder, baking soda, salt, and lemon zest in a large bowl.
03 - Add cold, cubed butter to dry ingredients. Use a pastry cutter or fingertips to cut in until mixture resembles coarse crumbs.
04 - Whisk heavy cream, egg, vanilla extract, and lemon juice in a separate bowl until combined.
05 - Pour wet ingredients into dry mixture. Stir gently until just combined to form a shaggy dough.
06 - Fold in blueberries carefully to distribute evenly without crushing them.
07 - Turn dough onto floured surface. Pat into a 7-inch diameter round, about 1 inch thick.
08 - Slice dough into 8 wedges. Transfer wedges to prepared baking sheet, spacing slightly apart.
09 - Lightly brush scone tops with heavy cream for a golden finish.
10 - Bake for 16 to 18 minutes until golden brown and cooked through. Cool on a wire rack.
11 - Whisk powdered sugar, lemon juice, and lemon zest until smooth and drizzle-able.
12 - Once scones are mostly cool, drizzle with lemon glaze. Allow glaze to set briefly before serving.