Preheat oven to 375 F and line a cookie sheet with parchment paper. Set aside.
In a large bowl, combine flour, sugar, baking powder and salt. Thoroughly cut in butter*
Measure out heavy cream into a measuring cup and add in the vanilla extract. Stir gently to combine. Carefully stir heavy cream/vanilla mixture into flour mixture. You do not want to over-mix, but due to the amount of dry ingredients it may be tricky to well incorporate the liquid and the dry mixes. You may briefly use an electric mixer on a low setting to help coax the dough to cling together.
Once dough is just beginning to cling together but is still somewhat shaggy, transfer to a lightly-floured surface.
Sprinkle the berries over the dough, and lightly work the dough and berries together until combined.
Divide the dough into 2 even pieces, and round each into a disk about 8" wide. Cut each into 8 wedges and transfer wedges to cookie sheet. Bake on 375F for 18-20 minutes.
While the scones cool, prepare your glaze by whisking together sugar, lemon juice, water, and vanilla extract.
Once scones are cooled, drizzle glaze lightly over the top of each scone. Allow it to sit and harden before serving.
* I prefer to freeze the butter, grate it using a box grater, and then cut it in that way. This method yields the flakiest scones, but is not mandatory -- you can use cold butter cut in with a pastry cutter. **frozen berries are easier/less-messy to incorporate into the dough, but either will work.