Center an oven rack, and preheat the oven to 375 degrees F.
In a large bowl, toss together the berries with the sugar and the brandy or vanilla. Set aside at room temperature while making the rest of the cake.
To make the topping, combine the sugar, flour, and ginger in a small bowl. Blend the butter into the dry ingredients, using either your fingertips or a fork, until the mixture forms crumbs. Put the topping in the freezer while you mix the cake batter.
To make the cake, combine the flour, cornmeal, sugar, baking powder, ginger, and salt in a large bowl. Add the butter and using your fingertips, work it completely into the dry ingredients. In a separate bowl, whisk the eggs and milk together and stir them into the dry ingredients until combined. Spread the batter into your buttered pan. Evenly distribute the sugared berries on top of the batter. Scatter the chilled topping over the berries. Place the dish in the center of the oven. Bake until the berries bubble and the cake is firm (ignoring those spots where the crumb topping has melted into the cake, since it's hard to tell in those oh-so-buttery spots), 40 to 45 minutes.
Cool the cake on a wire rack for 30 minutes and serve warm from the dish.
Well wrapped and stored at room temperature, this cake keeps for up to 2 days.
NotesUse a 2 1/2-quart square baking dish or 9-inch square cake pan, greased with 1 tablespoon of soft butter.