In a small heatproof bowl set over a saucepan of simmering water, heat ¼ cup of the cream, stirring often, until steaming. Remove bowl from pan and stir in chocolate until melted and smooth.

In a chilled bowl, using an electric mixer, whip remaining cream until soft peaks form. Beat in sugar and vanilla extract just until stiff peaks form.

Fold one-quarter of the whipped cream into chocolate mixture then fold back into the remaining whipped cream. Fold in two-thirds of the raspberries.

Spoon into serving dishes and top with remaining raspberries. Serve immediately or refrigerate for up to 8 hours.