Preheat oven according to package instructions.
Prepare an 8-inch baking dish with cooking spray.
Pour the entire can of black beans into a food processor.
Blend until smooth.
In a medium bowl, add the brownie mix with the blended black beans. Mix until well combined.
Pour the mixture into the baking dish. Smooth the top of the brownies. If desired, sprinkle the top with chocolate chips or nuts.
Bake according to package timing, which should be around 35-45 minutes. Baking times can vary from brownie mix and oven times though. They will be done when you insert a toothpick and it comes out clean.
You can serve as is, or ice them if you'd like. Enjoy!
