Puree the currants with sugar. Save a pair for decoration.
Heat the cream, add the sugar and pulp of the vanilla pod, stir vigorously with a whisk, bring to the boil briefly and then let it cool.
Gradually add the cream to the ricotta, stirring constantly. Beat until the ricotta becomes a very thick cream.
Fill glasses with the pureed currants and the ricotta cream. If you want, you can put a bonnet of whipped cream on it. Leave in the refrigerator for at least 4 hours