Preheat oven to 400F.
Prepare the bisctuis: In a food processor combine flouor, sugar, baking powder, salt, lemon zest, and butter. Pulse until the mixture becomes crumbly and the consistency of sand. Drizzle in cream and pulse until the mixture comes together and is the consistency of snow.
Place the dough onto a parchment lined cutting or pastry board, break into six evenly sized pieces. Form each piece into a 4" disc shape about 1" thick. Cover and refrigerate while preparing the filling.
In a large mixing bowl combine blackberries, sugar, corn starch, lemon juice, salt, and vanilla extract. Gently toss to evenly coat the berries.
Transfer the berry mixture to a 14" oval baking dish, 12" round skillet, or 9"x12" baking dish.
Remove the biscuits from the refrigerator. Place the biscuits evenly over the top of the berries. Use a pastry brush to brush each biscuit with cream and sprinkle coarse sugar on top.
Bake at 400 F for 30-40 minutes.
Cool for 5 minutes and enjoy warm with vanilla ice cream!