Preheat the oven to 180°C/gas mark 4. Grease eight to ten dariole moulds, ramekins or small cups with a little butter.
Using the paddle attachment on a stand mixer, cream together the sugar and butter until light and fluffy. This should take about 10 minutes. Scrape down the bowl from time to time to ensure the mixture is fully combined. Add the treacle and golden syrup and mix well.
Add the eggs one at a time, then add the self-rising flour after the eggs have been fully incorporated. Mix together, scraping down the sides of the bowl, until all the ingredients are fully combined.
Place the dates in a saucepan with the water and bring to the boil. Remove the pan from the heat and purée the date mixture with a hand-held blender. Add the baking soda to the date purée and blend again, then add the date purée to the cake batter and mix well.
Pour the batter into the greased moulds and bake for 20 to 25 minutes, until the cake shrinks away from the sides of the moulds and springs back when gently pressed with a finger.
While the puddings are baking, you can make the toffee sauce. Melt the butter and sugar together in a saucepan, then add the double cream. Bring to the boil, then reduce the heat and simmer until the mixture coats the back of a spoon.
Serve the puddings while still warm, drizzled with the toffee sauce. Serve with whipped cream.