According the packaging on Hotel Chocolat's Fudge Sundae, the caramel inside these truffles comes from Cartmel, the spiritual home of sticky toffee pudding. It was well worth the trip, because the gooey centre has a beautifully mellow flavour with what tastes like a hint of honey. There are also notes of hazelnut that you don't pick up at first, but then subtly make their way to the back of your throat.
I am not sure why it is called a fudge sundae because although there are a few fudge pieces scattered on top, the taste nor texture reminds me of a sundae. I keep wanting to call is a chocolate fondue because of its runny, melt in the mouth middle. But whatever it is called, it is absolutely delicious.