Warm together the ingredients until the butter has melted and the sugar dissolved and pour over the pudding as it comes out of the oven.
You can prick holes in the top to help the sauce soak in.
Notes
With the sauce incorporated into the Malva Pudding you hardly need anything else to accompany it, the cream being already inside! Just for appearances' sake though you might like to serve it with a conservative dollop of vanilla ice cream, or a few poached apricots and a drizzle of cream. The other compromise is to reserve some of the sauce to serve alongside the pudding rather than letting the whole amount soak in.