Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper. In a large mixing bowl, sift together the flour, sugar, baking powder, and salt. Add the cold butter cubes and use a pastry cutter or your fingertips to cut the butter into the dry ingredients until the mixture resembles coarse crumbs with some pea-sized bits.
Gently fold the blueberries and lemon zest into the flour mixture, distributing the fruit evenly without crushing them.
In a small bowl, whisk together the egg and buttermilk until combined. Pour this mixture into the dry ingredients and gently stir until just combined; the dough will be slightly sticky.
Turn the dough out onto a lightly floured surface and gently knead it a few times until it comes together. Pat the dough into a circle about 1-inch thick.
Use a sharp knife or a floured pastry cutter to cut the circle into 8 wedges. Transfer these wedges to the prepared baking sheet, spacing them apart slightly.
Bake in the preheated oven for about 15-20 minutes, or until the scones are golden brown on top and cooked through. You’ll notice a lovely aroma filling the kitchen as they bake.
Remove the scones from the oven and let them cool slightly on a wire rack. Serve warm or at room temperature, enjoying the flakey layers and bursts of blueberry with each bite.
