Preheat oven to 400 degrees. Grease a 9–or 10-inch square shallow baking dish or pie plate.
In a medium bowl, gently toss the berries with 3 Tbs. flour, ¼ cup sugar and zest. Transfer berries into the prepared pan. Set aside and reserve the bowl.
To make the cobbler topping, blend the 1 ½ cups flour, baking powder, baking soda, 2 Tbs. sugar (if using), salt and butter with your fingertips or a pastry blender or pulse in a food processor just until most of the mixture resembles coarse meal. Transfer to the same bowl used to mix the berries and stir in the buttermilk and maple syrup (if using) until well combined.
Using your fingertips, rub the buttermilk mixture until it begins to clump together. Take a heaping spoonful of dough and place it on top of the berries. Don’t cover the berries completely. Brush with melted butter or buttermilk and sprinkle with sugar, if desired. Place the dish on a baking sheet and bake for 40 minutes or until the fruit is bubbling and the top is golden and cooked through.