Cut butter into small chunks and then cut into flour with two knives or a pastry blender, until the butter pieces are no larger than a pea. Form a well in the center. Beat egg and pour into well. Stir until it starts to come together.
8 tablespoons unsalted butter, 1 large egg
Add the blackberries and carefully fold in until incorporated , then gently knead until dough forms a ball. If it seems too dry, add 1-2 tablespoons of milk. The dough should not be overly sticky.
On a sheet of parchment paper or flour-dusted countertop, pat the dough out into a flat circle about 1/2 inch tall. Using a large sharp knife or pizza cutter, slice each circle into 8 pieces.
Place scones 1 inch apart on a parchment lined baking sheet. Bake for 15-18 minutes or until golden brown.