Preheat the oven to 200º C.
Grease and flour 20 cm square cake tin.
Cream the butter and sugar together in a food processor until fluffy.
Add the golden syrup and eggs, a little at a time, and blend until smooth.
Add the flour and blend, at a low speed, until well combined.
Transfer to a bowl.
Blend the dates and boiling water in a food processor to a smooth purée.
Stir the bicarbonate of soda and vanilla into the date mixture
Pour the date mixture into the pudding batter and stir until well combined.
Pour the mixture into the cake tin and bake at 200º C until the top is springy and golden-brown (about 35-40 minutes).
Heat all of the sauce ingredients in a pan, stirring occasionally, until boiling.