• Prep Your Ingredients Preheat the oven to 400°F (200°C). Lightly grease a baking sheet or use parchment paper. Gather and measure all ingredients. If you’re using freshly milled flour, sift it thoroughly to remove any larger particles.
• Mix Dry Ingredients In a large mixing bowl, combine the flour, sugar, baking powder, and salt. Mix well to ensure an even distribution.
• Cut in the Butter Cut the cold butter into small cubes. Using two knives or a pastry blender, work the butter into the dry ingredients until the mixture resembles coarse crumbs.
• Add Wet Ingredients In a separate bowl, whisk together the milk and beaten egg. Add the blueberries and gradually stir this mixture into the dry ingredients until moistened.
• Knead and Shape the Dough Turn the dough out onto a lightly floured surface and knead briefly, about 5 or 6 turns. Pat or roll the dough out into a 1/2-inch thick round. Cut the dough into 8 wedge-shaped pieces and place them onto the prepared baking sheet.
• Bake Bake the scones in the preheated oven for about 15 minutes, or until they are golden brown on top. Remove from the oven and allow them to cool slightly on a wire rack.

Glaze

• Make the Glaze While the scones are cooling, prepare the glaze by whisking together the powdered sugar, milk, and vanilla extract in a small bowl. Drizzle the glaze over the warm scones.