Preparation

• Preheat your oven to 375°F (190°C).
• Chop the bittersweet chocolate and place it in a heatproof bowl along with the butter. Set the bowl over a saucepan of simmering water to create a double boiler. Stir until fully melted and smooth. Remove from heat and let it cool slightly.
• In a separate bowl, whisk the egg yolks with the granulated sugar and vanilla extract until the mixture becomes pale and fluffy, about 3-4 minutes.
• Gently fold the melted chocolate into the egg yolk mixture until well combined.
• In a clean bowl, whip the egg whites with a pinch of salt until stiff peaks form.
• Carefully fold one-third of the egg whites into the chocolate mixture to lighten it. Then gently fold in the remaining egg whites until there are no visible streaks.
• Grease individual ramekins with butter and dust with granulated sugar to prevent sticking.
• Spoon the soufflé batter into the ramekins, filling them about three-quarters full.
• Place the ramekins on a baking sheet and bake for 20-25 minutes until they have risen and the tops are set but the centers remain soft.
• Dust with powdered sugar and serve hot.