In a saucepan, combine the sugar, cornstarch, cinnamon, and nutmeg. Gradually stir in the water. Bring the mixture to a full boil, stirring constantly. Remove from the heat.
Divide the berries between 2 cake pans, 10 inches (25 cm) in diameter. Pour the hot liquid over the fruit.
Bake uncovered at 400°F(205°C) for 10 minutes.
Remove from the oven and dollop the cobbler topping over the fruit.
Continue baking until the topping is golden brown and baked through, about 15 minutes longer. Serve warm with crème fraîche, whipped cream, or ice cream.