Grease a 25 cm x 18 cm/10 in X 7 in non-stick baking tin that is at least 2.5 cm/1 in deep.
Place the dates in a pan with 300 ml/1/2 pint of water and bring to the boil, then simmer for 5 minutes until softened. Remove from the heat and stir in the bicarbonate of soda until the mixture stops foaming.
Place 50 g/2 oz of the butter and the caster sugar in a large bowl and cream together until light and fluffy, using an electric mixer, then beat in the vanilla essence. Gradually add the eggs, beating well after each addition.
Fold in the flour with a metal spoon and finally fold in the date mixture. Pour into the greased baking tin and cook for about 35-40 minutes until well risen and firm to the touch.
To make the toffee sauce, simply place the remaining 100g/4 oz of butter the dark muscovado sugar and golden syrup in a pan and heat gently, stirring until the sugar has dissolved. Bring to a simmer and cook for 2-3 minutes until thickened. Stir in the cream and allow to bubble down, then remove from the heat.
When the pudding is cooked, remove from the oven and after 5 minutes turn out on to a wire rack to cool completely. To serve, cut the pudding into portions and arrange on plates. Pour over some of the toffee sauce, then flash under a hot grill until bubbling, if liked. Add a scoop of ice cream and serve the remainder of the sauce separately, hot or cold.