Preheat oven to 375°. Combine brown sugar, balsamic vinegar and cornstarch in a medium mixing bowl. Add the strawberries, stirring well to totally coat the strawberries. Allow berries to sit at room temperature for about 10 minutes, stirring occasionally. Set the 2 T. diced butter aside.
In another bowl combine flour, brown sugar, baking powder, baking soda and salt. Mix well. Add the 5 T. diced butter and using a pastry cutter or your fingers, cut/rub the butter into the flour until mixture resembles coarse sand. Using a fork, stir in 1/2 cup buttermilk only until no dry flour shows. If you still see dry flour, add more buttermilk a little at a time, mixing well after each addition, until no more dry flour remains.
Butter a 10" iron skillet, an 8 X 8 baking pan, or a 1 ½ or 2 quart casserole dish. Pour the strawberries and all their juices into the baking dish. Dot with the remaining butter. Using your fingers, sprinkle the topping evenly over the berries. Bake for 30 or 35 minutes. Serve warm with vanilla ice cream.