Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper to prevent sticking and ensure even baking.
In a large mixing bowl, whisk together the all-purpose flour, 1 cup of sugar, baking powder, and a pinch of sea salt until well combined.
Add the cold, cubed butter to the dry ingredients. Using a pastry cutter or fork, cut the butter into the flour mixture until it resembles coarse crumbs with pea-sized pieces.
In a separate bowl, whisk together the cold buttermilk and eggs until fully combined.
Pour the wet ingredients into the dry mixture and stir gently with a spatula until just combined. Be careful not to overmix; dough should be slightly sticky.
Gently fold in the fresh blueberries, being careful not to break them apart.
Turn the dough out onto a lightly floured surface. Pat it into a rectangle about 1 inch thick. Cut the dough into triangles or use a round cutter to create scone shapes. Place them on the prepared baking sheet with space between each.
Brush the tops of the scones with melted unsalted butter. Bake in the preheated oven for 20-25 minutes or until lightly browned and a toothpick inserted into the center comes out clean.
Remove scones from oven and let cool on a wire rack. Prepare glaze by mixing sifted powdered sugar with 1 to 2 tablespoons of whole milk until desired consistency. Drizzle glaze over cooled scones.