First, mix flour, sugar, baking powder and salt into a large bowl until well combined.
Next, add lemon zest, lemon juice, egg, vanilla and milk. Stir, or fold with hands, until just combined.
Take your butter out of the freezer and add it to the dough. Use a fork to combine the butter with the dough.
Gently fold in your blueberries.
dust your work surface with a bit of flour and plop your scone dough right on top of it.
Once you've shaped it into a disk, cut it into triangles and place on a buttered baking sheet.
Brush each scone with egg mixture, sprinkle with granulated sugar.
Bake at 350 degrees for 30 minutes or until knife comes out clean.