Method:

Preheat the oven to 180°C/160°C fan/350°F. Grease your heatproof moulds with melted butter and dust lightly with flour.

Add the dates into a heatproof bowl and pour over the boiling water. Add the bicarbonate of soda, then leave the dates to soften and cool for 15 minutes. Transfer the dates and their soaking water to the bowl of a small food processor and blitz them to a smooth purée. 
Cream the butter and both sugars together in the bowl of a stand mixer fitted with a beater attachment, on medium–high speed, for 3–5 minutes, until light and fluffy. Add the egg and beat until combined. Add the flour and mix for about 1 minute on low speed until combined, then add the puréed dates and fold them through the mixture, using a spoon or spatula, until no streaks remain and taking care not to over-mix.
Pour the cake batter equally into the moulds.

Bake the puddings for 20–25 minutes, until the top of each pudding is springy to the touch. Remove to cool, then serve slightly warm with Toffee sauce