In a medium saucepan bring water and dates to the boil. Mix in the bicarbonate of soda. Let cool (careful the mixture will rise).
Cream the butter and sugar until pale. Add the eggs, one at a time, beating well after each addition. Sift in the flour. add the date mixture and the vanilla, and mix well with an electric hand mixer. Pour into a large rectangular ceramic baking dish, bake in the oven for approx 40 minutes.
To make the sauce put the caster sugar, cream and butter in a saucepan over a medium heat. Mix until well combined and smooth. Bring to the boil, then remove from the heat.
Pour the sauce over the pudding when plated and add a scoop of ice cream if you wish.