Combine dates, water and baking soda, stand 30 minutes.
Beat butter and sugar until light and creamy, beat in eggs one at a time.
Fold in date mixture and sifted flour.
Spoon evenly into greased lined 20cm deep round cake tin.
Bake in preheated oven, 50-60 minutes, or until cooked when tested.
To make caramel sauce; combine custard powder with 1/3 cup of evaporated milk in a pan, add remaining evaporated milk, extra brown sugar and golden syrup.
Stir over low heat until custard boils and thickens.