01 - Melt 7 oz chopped dark chocolate in a microwave-safe bowl or over a double boiler until smooth. Using a pastry brush or spoon, coat the insides of 6 silicone or paper cupcake liners with melted chocolate, creating an even layer. Place the liners on a tray and chill in the refrigerator for 20 minutes, or until set. Once firm, carefully peel off the liners, leaving you with chocolate cups.
02 - In a microwave or double boiler, gently melt 3.5 oz dark chocolate and let it cool slightly. In a chilled bowl, whip 3/4 cup heavy cream with 2 tbsp powdered sugar and 1 tsp vanilla extract until soft peaks form. Fold a spoonful of whipped cream into the melted chocolate to lighten, then gently fold the chocolate mixture into the remaining whipped cream until fully combined and smooth.
03 - Pipe or spoon chocolate mousse into each chocolate cup, filling about two-thirds full. Garnish with fresh berries, chopped nuts, mini marshmallows, chocolate curls, and edible gold decorations as desired. Chill the assembled cups in the refrigerator for at least 20 minutes before serving.