In large bowl, whisk together the flour, sugar, baking powder and salt. Add the cubed butter. Using your fingers, work the butter into the flour until the mixture resembles coarse meal. Add the frozen berries and mix to combine.
In small bowl, whisk together the heavy cream, egg and vanilla. Add the cream to the flour mixture and mix just until moistened.
Turn the dough out onto a lightly floured surface and shape into an 8-inch disc. Cut into 8 wedges. Transfer to a parchment-lined baking sheet allowing 2-inches between each scone. Refrigerate for 15 minutes.
Meanwhile, preheat oven to 400°F.
Bake chilled scones for 15-20 minutes or until lightly golden brown. Allow scones to cool 10 minutes before adding icing.
In small bowl, whisk together the powdered sugar and lemon juice. Drizzle over the cooled scones.