Combine the blackberries with water and spices in a medium saucepan, and bring just to boil. Reduce heat and cook on low for 30 minutes. Gently crush the berries against the side of the saucepan while it simmers. Without mashing the berries in the strainer, strain the berries through a fine sieve into a pyrex bowl. Add brown sugar and stir until dissolved. Set aside to cool.
Stir in Cognac or Brandy and pour into bottles. Tightly seal the bottles and store in a cool dark place for about 2 weeks.