For the sauce:
Preheat oven to 180 °C. Grease 23cm x 33cm rectangular baking dish.
Bring water and dates to the boil in a medium saucepan. Stir in the bicarb soda. Cool for 5 minutes or so.
Beat butter and sugar in a small bowl with electric beaters until fully mixed. Add the eggs, one at a time, beating well after each addition.
Stir in the vanilla. Stir in the flour and the date mixture. Pour into dish; bake for 40 minutes.
For the caramel sauce:
Stir sugar, cream and butter in a medium sacepan over medium heat, without boiling, until sugar dissolves and the butter has melted. Increase the heat a bit, stirring until it bools, then reduce heat and simmer for three minutes. Remove from heat and stir in the salt.
Serve the pudding with the sauce poured over
The pudding can be made several hours in advance and left in the baking dish until cutting, serving and reheating in a microwave (~45 seconds per slice). The sauce and pudding go well with vanilla ice-cream.
The pudding is quite rich, so servings don't have to be big. It could serve up to 20 people, each person getting a square with sauce and a scoop of ice-cream, or maybe a dozen people if they are having a bigger slice.