I was amazed how easy and how gorgeous these were! The recipe is from Nigel Slater's The Kitchen Diaries.
200g dark, fine quality chocolate (I use 70% cocoa solids)
100g caster sugar
2 lightly heaped tablespoons chocolate hazelnut spread (Nutella or similar)
Set the oven at 200 degrees C or gas 6. Butter 4 small ramekins or oven-proof cups.
Break the chocolate into rough pieces and put it in a bowl suspended over gently simmering water. Melt without stirring. I use a microwave but take care not to let the chocolate burn.
Separate the eggs then beat the sugar with the egg yolks until thick & creamy. In a separate bowl, whisk the egg whites until airy and stiff.
Stir the butter into the chocolate and leave to melt, then gently stir in the hazelnut spread. Fold the chocolate mixture into the yolks and sugar, then carefully fold in the beaten egg whites with a metal spoon. Take care not to overmix. Make certain there are no floating bits of egg white.
Scoop into the four dishes and place on a baking sheet. Bake for 12-15 minutes, till risen. The tops should be cracked and the centres still wobbly. Should you open one too early, it can go back in the oven.
Serve with cream, ice cream, yogurt or creme fraiche.
NB I made these after the main course had been eaten. Prepare the egg yolks and sugar, the chocolate mixture and have the whites ready to whisk. After the main course, give the yolks and sugar another beat, check the chocolate isn't setting (if it is, just give it a few seconds in the microwave to remelt) and whisk the whites. I cooked mine for 14 minutes in our fan oven at 180 degrees.