Add the black beans, cocoa powder, banana, maple syrup, salt, coconut oil, flour, and baking powder to a bowl or a food processor.
Using a stick blender or in your food processor, blend the ingredients until smooth.
Using a spatula, fold in the walnuts and the vegan chocolate chips.
Line a brownie pan with parchment paper. Pour and extend the batter.
Sprinkle extra chocolate chips over the top. Bake the black bean brownies for 20 minutes.