Preheat your oven to 350°F (175°C).
Prepare an 8x8-inch baking pan by greasing it lightly with oil or lining it with parchment paper.
In a medium bowl, combine the cocoa powder, vanilla plant-based protein powder, baking powder, and salt. Whisk them together until well mixed.
In a food processor, add the black beans, almond butter, maple syrup, and vanilla extract. Blend until smooth and creamy.
Pour the dry mixture into the food processor with the wet ingredients. Blend until you achieve a thick, smooth batter.
Pour the brownie batter into the prepared baking dish and spread it out evenly.
Bake in the preheated oven for 25-30 minutes. Check for doneness with a toothpick.
Let the brownies cool in the pan for at least 15 minutes before cutting into squares.