Dissolve the gelatin in 3 tablespoons of cold water and let it bloom for 5 minutes. Heat gently until dissolved, do not boil.

Break the chocolate into pieces in a heatproof bowl. Melt it over a double boiler or microwave in short bursts, stirring in between until smooth.

In a separate bowl, whip the heavy cream with sugar until soft peaks form. Avoid overwhipping.

Warm the milk in a small saucepan. Add melted chocolate and stir until combined. Then add vanilla extract.

If using, add dissolved gelatin to the chocolate-milk mixture and mix well.

Gently fold in the whipped cream using a spatula until smooth and fluffy.

Spoon or pipe the mousse into serving cups and refrigerate for 2-3 hours or overnight.

Top with fresh berries, whipped cream, mint leaves, or edible gold flakes before serving.