01 - Place dark chocolate in a heatproof bowl set over a pot of simmering water, stirring until smooth. Remove from heat and let cool slightly.
02 - In a clean bowl, whip the heavy cream until soft peaks form. Refrigerate until ready to use.
03 - Whisk egg yolks with vanilla extract in a separate bowl. Gradually stir in the cooled melted chocolate until fully incorporated.
04 - Beat egg whites with a pinch of salt until soft peaks form. Gradually add sugar and continue beating until stiff, glossy peaks form.
05 - Gently fold whipped cream into chocolate mixture, then carefully fold in beaten egg whites one-third at a time until fully incorporated.
06 - Spoon mousse into serving glasses or bowls. Refrigerate for at least 2 hours until set.
07 - Combine raspberries, powdered sugar, and lemon juice in a blender. Purée until smooth, then strain through a fine sieve to remove seeds. Chill until serving.
08 - Spoon raspberry coulis over each chilled mousse. Garnish with fresh raspberries, chocolate shavings, and mint leaves as desired.