Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper.
In a large bowl, whisk together the flour, sugar, baking powder, and salt.
Add the cold butter cubes to the dry ingredients and use a pastry cutter or your fingers to incorporate the butter until the mixture resembles coarse crumbs.
Gently fold in the huckleberries, being careful not to crush them.
In a separate bowl, mix the heavy cream and vanilla extract. Add the wet mixture to the dry ingredients and stir until just combined.
Turn the dough onto a floured surface and gently knead it a few times to bring it together. Shape it into a disk and cut it into 8 wedges.
Place the wedges on the prepared baking sheet, brush them with the beaten egg for a golden finish, and bake for 20-25 minutes, or until golden brown.
Let the scones cool slightly before serving.