Chop the dark chocolate into small pieces and place in a heatproof bowl. Melt in a microwave in 30-second intervals, stirring until smooth.

In a separate bowl, whip the heavy cream and sugar together until soft peaks form.

Fold the melted chocolate into the whipped cream mixture carefully until fully combined.

Add vanilla extract and fold again. Spoon into serving glasses and refrigerate for at least 2 hours before serving.