First prepare the date puree. Simmer the dates in the water over a low heat for about 10-15 minutes until they are soft and the water has almost evaporated. Process in a blender until they are smooth.
Preheat your oven to 175 deg C/gas mark 4.
Now make the toffee sauce. Pour half of the cream and the other ingredients into a thick-bottomed pan and mix well. Bring it to the boil, stirring with a wooden spoon, and continue to boil until it is golden brown. Remove the sauce from the heat, allow it to cool slightly, then whisk in the remaining cream.
Grease and line a baking dish, measuring approximately 30cm x 24cm x 6cm deep, with greaseproof paper.
Now make the sponge. In a food processor or mixer, cream the butter and sugar with the paddle, on a medium speed until it is light and fluffy. Add the eggs slowly, taking care that the mixture does not separate. (If this does happen, add a little of the flour and continue mixing for a minute or so.) Then fold in the sifted flour mixture slowly until it is smooth. Finally, add the warm date puree and mix well.
Spread the mixture in the baking tin and bake for about 50-60 minutes or until the sponge is firm to the touch.
Allow it to cool - it can be left in the tin.
Finish by removing from the tin and trimming the outside edges. Cut the sponge horizontally into three then reassemble in the baking tin spreading two thirds of the sauce between the layers.
Once you have assembled the pudding, reheat it in the oven at 175 deg C/gas mark 4 for 15-20 minutes then cut it into eight equal servings and top with the remaining toffee sauce. Serve the pudding with ice cream, soured cream or creme fraiche.