Preheat oven to 350°F and line an 8x8" baking pan with parchment. (The parchment makes it much easier to lift the brownies out of the pan, so I don't recommend skipping if possible.)
Add black beans, almond butter, vanilla and maple syrup to a food processor and process until as smooth as possible. Stop and scrape down the sides of the bowl a few times to make sure everything is evenly blended.
Add in the rest of the ingredients, except for the chocolate chips, and process again until combined. Scrape down the bowl as needed.
Remove the food processor blade and stir in the chocolate chips.
Spread the brownie batter in the lined baking pan. Top with extra chocolate chips and bake for 25-30 minutes, or until slightly puffy and set.
Remove from oven and allow to cool in the pan for about 10 minutes, then use the overhanging parchment to gently lift the brownies out and onto a cooling rack. These brownies are very soft just out of the oven, but they firm up as they cool. I recommend waiting till they're fully cooled before cutting into them! If you're feeling impatient, you can pop them in the fridge to speed up the process.
These brownies can be stored in an airtight container on the counter for 3 days. I like to keep them in the fridge, where they'll keep about 5 days. You can also freeze them for later.