WARM THE EGGS IN A DOUBLE BOILER. Whip them with an electric mixer, and gradually beat in the sugar. Beat until the mixture is thickened and forms soft peaks. Soften the gelatin in the water and then dissolve over hot water. Beat the cream to soft peaks. Fold the gelatin and vanilla into the eggs and then fold in the whipped cream. Fold in the chestnut puree and the candied chestnuts. Fill the crust and refrigerate to set. Top with sweetened whipped cream.