01 - Melt the dark chocolate in a heatproof bowl over simmering water, stirring until smooth. Remove from heat and allow to cool slightly.
02 - Whisk egg yolks with vanilla extract and half of the sugar (2 tbsp) until pale and creamy.
03 - Gently fold the melted chocolate into the egg yolk mixture until well incorporated.
04 - In a separate bowl, beat the egg whites with remaining sugar (2 tbsp) until stiff peaks form.
05 - Whip cold heavy cream until soft peaks form.
06 - Fold the whipped cream into the chocolate mixture until fully combined.
07 - Gently fold in the beaten egg whites in thirds until the mixture is smooth and airy.
08 - Divide the mousse evenly among 6 serving cups or glasses.
09 - Refrigerate for at least 2 hours until set.
10 - Top each mousse cup with fresh raspberries, chocolate shavings, and mint leaves as desired before serving.