Bring the crème de marrons to lukewarm by placing in a bowl on top of boiling water.

Chop the chocolate and melt in a double boiler. When the chocolate is melted, add the lukewarm crème de marrons and mix well. Remove from double boiler and reserve.

Whip the crème fraîche and incorporate the zest of one lemon. Add half of the whipped cream mixture to the chocolate/crème de marrons and mix well to lighten it. Delicately add the remaining half and pour in small bowls.

Refrigerate at least 2 hours before serving and always bring to room temperature for 20 minutes before serving.