Preheat the oven to 400 F. Grease a baking sheet and set aside.
In a large bowl, whisk together the flour, sugar, baking powder and salt. Using a pastry cutter or two forks, cut in the cold butter until the mixture is crumbly.
Add in the buttermilk, yogurt and vanilla and bring together into a dough. Add in the egg and work together. Fold in the fresh blackberries.
Turn the dough out onto a floured surface and press into a disc ½” thick. Using a biscuit cutter or glass, cut as many scones out of the disc as you can. Place scones onto the greased baking sheet.
Fold the dough back together, press out into a disc and cut scones out as many times as necessary until all of the dough is made into scones.
Place into the oven to bake for 30-35 minutes or until the scones are golden brown around the edges and baked through. Remove from the oven and place on a cooling rack to cool.
While the scones are cooling, make the glaze by whisking the powdered sugar and milk together in a small bowl until a smooth glaze has formed.
Once the scones are cool, spoon glaze onto each one. Let set for a few minutes. Serve and enjoy!
Notes
For a thinner glaze, add milk a ½ tsp at a time. You could also glaze the scones while they are still a little warm. If you want a thicker glaze, do the opposite and only add milk into the powdered sugar a tablespoon at a time. Whisk well to determine the consistency before adding more milk.
For flakier scones, sprinkle a little flour onto the dough and fold it over. Repeat that a couple of times before flattening into a disc to cut into scones.