Blackberry brandy is a blackberry flavored liqueur found in some drink recipes. Though referred to as a brandy, it is really a flavored liqueur. It is not nearly as commonly used as some of it's cousins such as apricot, cherry, and peach brandy. I know of no examples of a true blackberry eau de vie but one might exist somewhere.
Most blackberry brandies you will find are pretty low quality. This include DeKuyper, Hiram Walker, Leroux, and Mr Boston brands. With these products you are getting a sweet, rather simple flavor profile. The blackberry fruit flavor will be rather one dimensional. Unfortunately there are not a lot of other options.
Probably the best example that is widely available is Bols Blackberry Brandy. It will be a step up from the other brands but not a very big step. Clear Creek distillery makes a blackberry liqueur that might be good. I have not tried it but I have tried some of their eau de vies and they high quality products.
Have you found a good blackberry brandy? Is so please comment below to spread the word.