Preheat oven to 350 degrees. Line a 4x8 loaf pan with parchment paper, so that there is an overhang on each side. You will need the overhang to remove the brownies from the pan.
In a blender or food processor, puree the black beans with the non-dairy milk milk and the yogurt. Stop periodically and scrape down the sides and make sure that all the bean skins are gone. You want this batter to be really smooth.
Transfer the bean mixture to a bowl and add the melted vegan buttery spread, sugar, cocoa powder, and baking powder.
Stir well. Spoon batter into the loaf pan and smooth it out with the back of a spoon.
Bake at 350 degrees for about 30 minutes. They may seem a teeny bit underdone in the middle - that's okay! They will firm up as they cool, plus this is a fudgy brownie, not a cake-like brownie.
Allow to cool completely in pan, then lift the whole brownie out by pulling up on the edges of the parchment paper. Transfer to a cutting board and slice into 8 pieces using a very sharp knife.
Notes
This recipe makes 8 brownies. Serving size is one brownie.Store leftover brownies in the refrigerator.You can use a different type of bean if you like, but the color will be different.If you can eat dairy, feel free to use dairy products in this recipe.