Preheat the oven to 180°C (350°F/Gas 4). Grease 10 small pudding moulds and divide them between two baking sheets.
Put the dates and 300ml (101?2 fl oz) water in a saucepan and place over a medium–high heat. Bring the mixture to the boil and then simmer for approximately 20 minutes or until the liquid has reduced by half and the dates have completely softened.
Cream the butter and sugar in a large bowl with an electric hand mixer until light and pale. Add one egg at a time, mixing after each addition, until they are incorporated. (If you add the eggs all at once, the mixture can split.)
Blitz the dates with a hand blender while still hot, until smooth, then stir through the bicarbonate of soda. Fold the date mixture, flour, bananas and vanilla extract into the pudding mixture until you have a smooth batter. Divide the mixture between the six moulds and bake in the oven for 20–25 minutes.
Meanwhile, make the salted caramel sauce. Place the butter, sugar and golden syrup in a saucepan and bring to a gentle boil until the sugar is dissolved. Add the cream, vanilla extract and salt and whisk together. Bring to a steady simmer for 3 minutes until the sauce is sticky and thick.
Insert a metal skewer into the centre of one of the puddings; if it comes out clean, the puddings are ready. Remove from the oven and allow to cool slightly before inverting them onto serving plates.