Preheat oven to 350 degrees.
Spray a 9x13 baking dish with cookie spray or line with parchment.
Combine butter, sugar, unsweetened baking chocolate, and vanilla together in a microwavable bowl. Heat in microwave in 30 second intervals, until chocolate is melted. Stir to combine and set aside.
In a large mixing bowl, combine flour, cocoa powder, salt, and baking powder.
Add in eggs, one at a time, and combine well.
Pour in prepared coffee and chocolate mixture. Stir to combine.
Add in chocolate chips, 4 oz of blackberries and pecans (if desired). Combine and Pour into baking dish.
In a small mixing bowl, crush other 4 oz of blackberries and swirl into top of uncooked brownie batter.
Bake in oven for 30-35 minutes, or until toothpick inserted comes out clean. Cool in baking pan. Remove from pan, cut, and serve. Enjoy!