1. Coat a 2 1/2-quart casserole dish with nonstick cooking spray. Combine the filling ingredients in a medium-sized bowl, and set aside for 15 minutes to allow the juices to develop. Then stir gently to mix well, and transfer to the prepared dish.
2. Combine all of the topping ingredients except for the buttermilk in a medium-sized bowl, and stir to mix well. Add the buttermilk, and stir just until the dry ingredients are moistened. Drop heaping tablespoonfuls of the batter onto the blueberry mixture to make 8 biscuits.
3. Bake at 375°F for about 45 minutes, or until the filling is bubbly and the topping is golden brown. If the topping starts to brown too quickly, cover the dish loosely with aluminum foil during the last 10 minutes of baking. Remove the cobbler from the oven, and let it sit for 10 minutes.