Whilst chopping the dates, ensure there are no stones or tough skins left behind. Soak the dates in the bicarb and hot water for 1 hour.
Preheat the oven to 180 C / Gas 4.
Beat the 110g butter until light and fluffy. Beat in the icing sugar. Then beat in the eggs one at a time, then the vanilla. Sift in the flour and baking powder, and combine. Finally, fold in the entire date mixture.
Pour mixture into a 25cm round loose bottomed cake tin. Bake in the preheated oven for 40 to 60 minutes (the pudding should not wobble).
For the toffee sauce, combine the butter, brown sugar and cream in a pan and bring to the boil, stirring occasionally. Simmer until sugar is dissolved.
Cut warm pudding into generous portions and pour some sauce on each piece and enjoy!