How to Make It
In a medium saucepan, combine the blackberries with the water, cloves, peppercorns, cardamom, cinnamon and bay leaf and bring just to a boil. Cook over low heat for 30 minutes, gently crushing the berries against the side of the saucepan. Strain the berries through a fine sieve into a heatproof bowl without pressing on the berries. Stir in the brown sugar until dissolved. Let cool.
Stir in the Cognac and pour into bottles. Seal the bottles tightly and store in a cool dark place for at least 2 weeks before serving.