Preheat oven to 350 degrees F.
Blitz the sugar, lemon zest, flour, baking powder, and salt in a food processor.
While pulsing, add in the butter 1 tablespoon at a time.
Once the mixture resembles dry sand, add in the sour cream, vanilla, and egg. Blitz until combined.
Lightly dust a clean counter top with flour.
Turn the dough mixture out onto the counter top. Gently press the dough to flatten it. With gentle folding motions, incorporate the berries into the dough. Continue to fold until just combined, careful not to overmix.
Shape the dough into a circle. Using a bench scraper or a long knife, cut the dough into 8 triangles.
Place the 8 triangles onto the a baking sheet lined with parchment paper.
Brush a bit of heavy cream onto each scone. Dust them all with sugar.
Bake 20-22 minutes, or until the scones are baked through, and just beginning to brown on the bottom.
While the scones are baking, prepare the glaze. Combine the lemon juice, powdered sugar, vanilla, and heavy cream.
Once the scones have been removed from the oven and slightly cooled, drizzle the glaze onto each scone with a spoon or piping bag.
These are best served same day, but will stay good for overnight in an airtight container.
