Cream the butter and sugar together in a food processor until pale and fluffy. Add the golden syrup, treacle and eggs, a little at a time, and whisk until smooth. Add the flour and blend slowly until well combined. Transfer to a bowl.
In the meantime, blend the dates and boiling water in a food processor to a smooth purée. Mix in the bicarbonate of soda and vanilla.
Stir the date mixture into the pudding batter and mix until well combined.
Pour the mixture into the moulds and bake for 20-25 minutes, or until the top is golden and springy.
To prepare the sauce, heat all of the ingredients in a pan, stirring occasionally, until boiling.
To serve, remove the puddings from their moulds and place onto individual serving plates. Pour over the sauce and serve with a scoop of vanilla custard or ice cream.