Preheat oven to 400ºF. Grease an 8x8-inch baking pan and set aside.
In a bowl or directly in your greased baking dish, toss blackberries with brown sugar, flour, lemon zest, vanilla, cinnamon and salt.
Bake for 12-14 minutes, until fruit is bubbly.
Combine all biscuit ingredients in a medium bowl.
Spoon scoops of biscuit dough over on top of berries.
Bake for 22-24 minutes until the biscuits are golden brown.
Notes
I used an 8x8-inch baking dish, but you can use other sizes. A 9x13 baking dish will have a thinner layer of blackberries and will need more, smaller scoops of biscuit dough. It will cook up a little faster, so just keep an eye on your oven when it is nearing the end of bake time.
Tips
Always wash your berries well. Let them dry or pat them dry with a paper towel to avoid excess water getting into your cobbler.
Save on dishes and make the blackberry mixture right in the baking dish!
Use a cookie scoop to help you get evenly-sized biscuit toppings.