Melt butter in a medium saucepan. Remove from the heat and add ginger and HALF the brown sugar (150g). Stir and then add eggs, stirring well after each. Lightly mix in the flour and spices until just combined. Pour into prepared dish, evenly sprinkle over remaining HALF of the brown sugar and gently pour over 1 cup of boiling water. Do not be alarmed if the pudding looks a little odd, in the oven the water and brown sugar will combine to magically form a sauce under the pudding.
Cover the pudding loosely with a large piece of foil and bake for 35 minutes. Remove foil and bake for another 5 minutes until golden.
