Preheat the oven to 375° F. In a 9×13 inch baking dish toss the peaches and blackberries with 1/4 cup brown sugar, maple syrup, and butter. Bake for 10 minutes.To make the batter. Stir together the flour, 3/4 cup brown sugar, baking powder, ginger, cinnamon, and salt. Add the milk, candied ginger pieces, and vanilla. Mix until just combined.Pour the batter over the peaches and blackberries, do not stir. Bake 50-55 minutes, until the center is just set and the edges begin to brown.Serve the cobbler warm or at room temp with ice cream. Enjoy!!