01 - Place chopped dark chocolate in a heatproof bowl set over a pot of simmering water, creating a double boiler. Stir continuously until completely smooth and melted. Remove from heat source and allow to cool for 5 minutes.
02 - In a chilled mixing bowl, beat the heavy cream using an electric mixer or whisk until soft peaks form. Place in refrigerator to maintain temperature until ready to fold.
03 - Whisk egg yolks with vanilla extract in a separate bowl. Gradually pour the cooled melted chocolate into the yolk mixture, stirring constantly until fully incorporated and smooth.
04 - Using a clean bowl and beaters, beat egg whites with salt until soft peaks form. Slowly add granulated sugar while continuing to beat until stiff, glossy peaks form.
05 - Gently fold whipped cream into chocolate mixture using a rubber spatula. Carefully fold in beaten egg whites in three additions, maintaining as much air as possible. Stop when just combined.
06 - Distribute mousse evenly among serving glasses or bowls. Refrigerate for minimum 2 hours or until completely set.
07 - Combine fresh raspberries, powdered sugar, and lemon juice in a blender or food processor. Purée until completely smooth, approximately 30 seconds.
08 - Pour raspberry purée through a fine mesh sieve into a clean bowl, pressing with a spoon to extract liquid while removing seeds. Refrigerate until serving.
09 - Spoon chilled raspberry coulis over set chocolate mousse. Garnish with fresh raspberries, chocolate shavings, and mint leaves. Serve immediately.