Strain the mixture, you will get about 1/2 cup of juice. save the solid part.
Preheat oven to 180C and prepare a 12 cup baking tray.
In a bowl mix together flour, sugar, cocoa, baking soda, coffee and salt. Add the vanilla extract, oil, blackberry solid and milk. Using a wooden spoon mix the batter well and keep mixing until you get a smooth batter.
Divide batter between 12 baking cups . Bake for 18-20 or until a toothpick inserted into the center comes out clean. Remove from the oven and allow to cool to room temperature.
Mix chopped chocolate and blackberry juice and heat in a microwave safe bowl for 1 minute. leave for a minute and whisk well until smooth. let it completely cool for about an hour. beat ganache for 2 minutes. now using piping beg or pastry beg pipe on cooled cupcakes. garnish with fresh blackberry.