Toss all filling ingredients together in a casserole dish and let stand until juicy (about 30 minutes)

Preheat oven to 400°F

Sift together flour, baking powder, soda, salt, and 2 teaspoons sugar in a bowl

Blend in butter with your fingertips or a pastry blender until mixture resembles slow cooking oatmeal flakes

Stir in buttermilk with a fork until combined; do not over mix

Drop rounded tablespoons of dough over filling, leaving spaces in between to allow topping to expand; sprinkle with remaining sugar

Bake cobbler in middle of oven until fruit is tender and topping is golden, about 60 minutes (watch the browning as it may have to be covered with foil at 30 minutes to prevent over-browning)

Cool slightly, about 15 minutes, and serve warm with vanilla ice cream