This chocolate mousse is super easy with only 3 ingredients, and perfect for both kids and adult parties.
Heat chocolate, half the cream and the marshmallows in a dry, heatproof bowl over a pot of simmering water, stirring until melted and smooth (about 10 minutes). Remove from heat and allow to cool to room temperature.
Beat remaining cream to soft peaks and fold through chocolate mixture. Pour into glasses or bowls and refrigerate for at least 6 hours or overnight before serving.