01 - Preheat the oven to 390°F. Generously butter two 6.8 oz ramekins and dust them with a little sugar, tapping out the excess to ensure even coating.
02 - Set a heatproof bowl over simmering water. Combine chocolate, butter, and milk in the bowl, stirring constantly until melted and smooth. Remove from heat and let cool slightly.
03 - In a clean, dry bowl, beat egg whites with salt until soft peaks form. Gradually sprinkle in granulated sugar while continuing to whisk until glossy, stiff peaks form.
04 - Stir egg yolks and vanilla extract into the slightly cooled chocolate mixture until completely smooth and incorporated.
05 - Gently fold one-third of the meringue into the chocolate base to lighten the mixture. Carefully fold in remaining whites until just combined, maintaining as much air as possible.
06 - Divide soufflé mixture evenly between prepared ramekins. Run your thumb around the inside rim of each ramekin to create a clean edge for even rising.
07 - Bake for 12-15 minutes until soufflés have risen well above the rims and have a slight wobble in the center—overbaking will cause them to collapse.
08 - While soufflés bake, whip cold heavy cream with powdered sugar and vanilla extract until soft peaks form. Keep chilled until serving.
09 - Dust hot soufflés with confectioners sugar and serve at once with a generous dollop of vanilla cream. Soufflés begin falling within minutes of leaving the oven.