Chop the dates and place them in a bowl. Pour over the boiling water and let them soak for 30 minutes until soft.
In a large mixing bowl, cream the butter and muscovado sugar with an electric mixer until light and fluffy.
Beat in the eggs one at a time, then mix in the vanilla and black treacle.
Stir the bicarbonate of soda into the flour. Add half the flour and half the milk to the bowl and mix gently.
Add the remaining flour and milk, stirring until smooth.
Mash the softened dates into a rough pulp and fold them into the batter.
Grease pudding moulds with butter and spoon in the mixture.
Bake in a preheated oven at 338°F (170°C) or 302°F (150°C) fan for 50 minutes, until risen and a toothpick inserted comes out clean.
Meanwhile, make the sauce by melting muscovado sugar, butter, and half the cream in a saucepan over medium heat, stirring until dissolved.
Add the black treacle and cook for 2–3 minutes until slightly thickened and glossy. Remove from the heat, pour in the remaining cream, and stir until smooth.
Cool the pudding for 10 minutes, then poke holes with a skewer and pour over half the sauce. Let it soak for 10 minutes.
Serve warm with the rest of the toffee sauce and a scoop of vanilla ice cream if you like.
Notes
Soak the Dates Fully: I like to let the dates sit for the full 30 minutes so they’re soft enough to mash easily into the batter.Cream Butter and Sugar Properly: I beat mine until pale and fluffy; it makes the sponge lighter and helps it rise well.Check Doneness Early: I usually test at 45 minutes with a toothpick to keep the pudding soft and not dry.Warm the Sauce Before Serving: I reheat the toffee sauce gently so it’s silky and pours easily over the pudding.