Preheat oven to 375 degrees F. Grease a 9-inch square (or 2½-quart) baking dish.
Prepare the Berries: In a medium bowl, toss the berries with the sugar and brandy; set aside.
Prepare the Crumb Topping: In a small bowl, whisk together the brown sugar and flour, then stir in the crystallized ginger. Blend the butter into the mixture with your fingertips or a fork until crumbs form. Place the bowl in the freezer while you prepare the cake.
Prepare the Cake: In a large bowl, whisk together the flour, cornmeal, sugar, baking powder, ground ginger and salt. Add the butter pieces and, using your fingertips or a pastry blender, work into the flour mixture until it is completely incorporated and there are no pieces larger than a pea remaining.
In a measuring cup or small bowl, whisk together the milk and eggs, then add to the flour mixture. Using a rubber spatula, gently stir the batter together until no pockets of dry ingredients remain. Spread the batter in an even layer in the prepared pan. Using a slotted spoon, remove the berries from the bowl and scatter over the cake batter. Break up the crumb topping into large pieces and scatter over the berries.
Bake until the berries are bubbling and the cake is firm, 40 to 45 minutes. Place the pan on a wire rack and cool for at least 30 minutes before serving. The cake can be stored, covered, at room temperature, for up to 2 days.