1. Put dates in a bowl and pour 1 cup very hot water over them. Working in the water, remove skin and pits from the dates. Coursely chop them.
2. Put the dates, 1 cup of water, baking soda and vanilla in medium saucepan. Bring to a boil and then simmer for about 2-3 minutes. (watch carefully as it will foam from the baking soda.)
3. Preheat oven to 350 degrees and grease a large Pyrex pan or 12 ramekin.
4. Combine flour, baking powder, sugar and salt in a medium bowl.
5. In the bowl of a mixer, cream butter. Slowly add the mixed dry ingredients and then the egg. Add date mixture and mix to combine.
6. Spoon mixture into pan or ramekin until slightly less than ½ full.
7. Put in preheated oven and cook for 25 minutes or until toothpick comes out clean.
8. Combine all the ingredients for toffee sauce in saucepan and bring to simmer, stirring until sugar dissolves. Cook for about 5 minutes, stirring occasionally, until slightly thickened.
9. When pudding is removed from oven, use skewer to poke holes over the top and along sides. Pour 2/3 of the sauce over the top and put back in oven for about 2 minutes. Serve with reserved sauce and vanilla ice cream or crème fraiche.