It sounds weird, but I'd never thought of folding jam into a cake batter before. Fruit, yes - mashed, chopped or left whole. But now I know the flavour and moisture that goes into a cake by adding jam, you can expect to see a whole load more jammy cakes here.
Nigella writes that the recipe is simple and quick - and it is. But what I think is really important is that depending on the type of morello cherry jam you use, you do have to cut back on the sugar. I bought the best quality cherry jam I could find, which I knew would be less sweet than the cheaper kinds. And I played it safe and took out about 30g sugar - and it all paid off. The result was a sweet chocolate cake with slightly tart cherry jam rippled through it, which worked brilliantly.
The cakes are topped with a swirl of the dark chocolate ganache that I love - and then with a cherry. My ganache was a bit runnier than the icing in the book, but hey - these things happen and no one complained. These cakes look amazing and taste great. Do consider them for a cake stall/birthday party/family gathering/rainy afternoon this summer.
You can find the recipe here on Nigella's website.