Preheat the oven to 190 degrees C and lightly butter a baking dish.
In a bowl, mix the pears with half the sugar, 1 tablespoon flour, ginger powder, candied ginger and half the cinnamon.
In another bowl, mix together the flour, oats and remaining sugar and cinnamon with the butter and water to form a crumb. Sprinkle evenly over the fruit mixture and bake for 40 mins or till the fruit is bubbling and the crust is golden.