Preheat your oven to 350°F (175°C). Grease an 8x8-inch baking pan or line it with parchment paper for easy removal.
In a blender or food processor, combine the drained and rinsed black beans, eggs, neutral oil, sweetener of your choice, cocoa powder, baking powder, and ground cinnamon.
Blend the ingredients until smooth and well combined, scraping down the sides of the blender or food processor as needed to ensure all the ingredients are incorporated.
Once the mixture is smooth, pour it into the prepared baking pan, spreading it evenly with a spatula.
If desired, sprinkle chocolate chips or chunks on top of the batter for extra chocolatey goodness.
Place the baking pan in the preheated oven and bake for 25 to 30 minutes, or until the edges are set and a toothpick inserted into the center comes out mostly clean with a few moist crumbs attached.
Remove the brownies from the oven and allow them to cool in the pan for at least 10 minutes before slicing and serving.
Once cooled, slice the brownies into 12 squares. Serve and enjoy your delicious Blender Black Bean Brownies!