1. Preheat the oven to 375°F (190°C). Grease 4 ramekins with butter and dust with a bit of sugar to prevent sticking.
2. Separate the eggs. Place the whites in a clean, dry bowl, and set the yolks aside.
3. In a heatproof bowl, combine the dark chocolate and butter. Melt them together over a pot of simmering water, stirring occasionally until smooth. Remove from heat and let cool slightly.
4. In a medium bowl, whisk the egg yolks with 1/4 cup (50g) of the granulated sugar until pale and creamy. Gradually add the melted chocolate mixture, stirring continuously until well combined. Add the vanilla extract and a pinch of salt, mixing well.
5. In a clean bowl, use an electric mixer to beat the egg whites until soft peaks form. Gradually add the remaining 1/4 cup (50g) of granulated sugar and continue to beat until stiff peaks form.
6. Gently fold about a third of the beaten egg whites into the chocolate mixture to lighten it. Carefully fold in the remaining egg whites until just combined.
7. Divide the soufflé mixture evenly among the prepared ramekins, filling them almost to the top but leaving a small space to allow the soufflés to rise.
8. Place the ramekins on a baking sheet and bake in the preheated oven for 15-20 minutes, or until the soufflés have risen and are set but still slightly wobbly in the center.
9. Remove the soufflés from the oven and dust with powdered sugar if desired. Serve immediately, as soufflés tend to deflate quickly.
• Protein: 6 grams
• Sugar: 25 grams
• Fats: 15 grams
• Saturated Fat: 8 grams
• Carbohydrates: 30 grams