I can say that if you have a sweet tooth then you will LOVE this! It's a lot creamier than I expected, and is extremely rich as it contains double cream as well as white chocolate. You're supposed to heat the sauce for 15 seconds in the microwave, but I scooped it straight from the jar and ate it as it was - I'm sure Nigella would approve!
This would probably be great poured over puddings or icecream (as it's meant to be), although I haven't tried either yet.
There's also a salted caramel version which I'm hoping to try at some point, as well as chocolate truffle. They're £2.99 a jar which sure ain't cheap, but then this is M&S quality we're talking about...
I would recommend this if you have a sweet tooth or if you're a white chocolate lover, but otherwise you might want to try try the chocolate truffle or salted caramel sauces instead.
Have you tried any of these M&S sauces? If so what did you think?