Preheat oven to 350°.
Heat chocolate chips in the microwave, 30 seconds at a time, until melted and smooth.
In a food processor puree the black beans and the vegetable oil. Transfer to a bowl. Whisk in milk, vinegar and vanilla.
In a separate bowl whisk flour, sugar, cocoa, baking soda and salt.
Pour the black bean mixture into the flour mixture and whisk until just combined. Fold the melted chocolate into the black bean brownie mixture.
In a food processor pulse 70% chocolate until it resembles coarse crumbs. Fold into batter.
Pour batter into a lightly greased, oven safe baking dish. Bake 25 minutes, or until a toothpick inserted into the center comes out moist. Remove from oven and let sit 10 minutes or until they are cool enough to handle.
Break up the brownie and add to a large bowl, tearing it apart so it resembles course crumbs. Scoop about 2 tablespoons of brownie into the palm of your hand and roll into a ball. Repeat with remaining brownie.
In a small bowl add ½ tablespoon of sugar and ½ tablespoon of cocoa. Toss half of the brownie truffles in this mixture. Add ½ tablespoon of chile powder to this small bowl, and proceed to toss the remaining brownie truffles in the chile mixture.
Store in the fridge in an airtight container until ready to serve.