Steps

• Preheat your oven to 200°C (390°F). Grease the insides of your ramekins or muffin tin with a bit of butter to ensure easy removal of the cakes later.
• Melt together the chocolate and butter. Do this over a double boiler or gently in a microwave in 20-second intervals, stirring in between until smooth.
• In another mixing bowl, whisk together sugar, eggs, and egg yolks until the mixture becomes pale and thick. This takes about 3-5 minutes of vigorous whisking.
• Gradually fold the melted chocolate mixture into the egg mixture, keeping the integration gentle to maintain airiness.
• Sift flour into the batter, adding a pinch of salt and vanilla extract. Blend these ingredients carefully until just incorporated to avoid deflating the mixture.
• Divide the batter evenly among the prepared ramekins, filling them about three-quarters full. Place them on a baking tray.
• Bake them in the preheated oven for 10-12 minutes. The cakes should have firm edges but the centers should be soft.
• Allow the cakes to cool for a few minutes before gently running a knife around the edges and tipping them onto plates to serve.