When pierced with a spoon, the inside should spill out in a wave of molten chocolate lava. It's all in the timing, so keep an eye on these little puds for the last minute or two of cooking, and be brave when turning them out.
125g butter, plus 2 tsp extra
150g bittersweet dark chocolate, chopped
2 eggs, plus 2 egg yolks
1 tsp vanilla extract
35g plain flour, sifted
Heat oven to 170C. Use 2 tsp butter to grease four 150ml heatproof souffle moulds, or ramekins, and place on a baking tray.
Melt the butter and chocolate in a heatproof bowl set over a pot of gently simmering water. Using an electric beater, beat the eggs, yolks, sugar and vanilla for a minute or two until pale. Fold in the flour, then fold in the chocolate mixture. Pour into the moulds to fill by three-quarters.
Bake for 10-12 minutes until risen, when the cake is set but the centre still moves a little when jiggled. Remove from the oven and from the tray.
Run a palette knife around each pudding, gently invert on to warm plates and serve immediately.
Tip: You can prepare these ahead and refrigerate the moulds for two or three hours. If baking from cold, add another minute or two to the cooking time.