Preheat the oven to 350° and grease a 9x13-inch Pan or iron skillet if Preferred.
Make the filling: In a large bowl, gently fold the berries, Sugar, Cornstarch, lemon Juice, and Vanilla extract together until combined. Spread into Prepared pan.
Make the topping: Whisk the flour, sugar, baking Powder and salt together in a large bowl.
Using a fork, Cut the butter into the mixture until you see Pea sized crumbs.
While slowly stirring, slowly pour in 1/2 cup buttermilk. Mix until Combined.
Take handfuls of dough and gently flatten out. Place dough over the top of the berry filling.
Brush the top of the biscuit dough with 1 Tbsp buttermilk and then sprinkle with sugar.
Bake for 45-55 minutes, or until golden brown and biscuit topping is cooked through.
Insert a toothpick into the topping, if it comes out clean, it is Cooked through.
The Cobbler is done. Remove from oven & let Cool for 5-10 minutes before Serving.