Preheat the oven to 160°C. To make the sticky toffee pudding, grease a 20cm round ovenproof dish with a little butter.
Beat the softened butter and light muscovado sugar together in a freestanding mixer until light and fluffy, scraping down the sides now and then if needed.
Add the golden syrup, treacle, and vanilla and continue to mix. Add in the eggs and beat together.
Turn down the mixer to a slow speed and add the flour in gradually. When this is mixed well turn the mixer off.
Bring 250ml of water to a simmer in a small saucepan with the chopped dates. After cooking for a few minutes add the bicarbonate of soda. Be careful as the mixture will foam up when the soda is added.
Add this to the flour mixture while still hot and mix well until the two are combined.
Pour the mixture into the prepared baking dish. Bake for 45-50 minutes, or until firm and slightly springy to the touch.
Meanwhile, make the toffee sauce. Melt the unsalted butter, dark muscovado sugar and golden syrup together in a small pan until the sugar has dissolved.
Add the double cream, vanilla extract and salt and bring to a steady simmer for 3 minutes until the toffee sauce has nicely thickened. Remove from the heat.
Drizzle the sticky toffee sauce all over the pudding.
Serve in the centre of the table topped with more toffee sauce and a scoop of vanilla ice cream.