A can of black beans and Duncan Hines brownie mix is all you need for these moist brownies.
- Preheat oven to 350°F. Spray a 9x13-inch baking pan with cooking spray.
- Pour beans with their liquid into a food processor or blender and blend until completely smooth. Add brownie mix and continue to process until completely smooth.
- Pour into prepared pan and spread evenly to the edges.
- Bake in centre of oven 22 to 26 minutes, or until toothpick inserted 1-inch from edge of pan comes out clean. Let cool completely. Sprinkle with powdered sugar, if desired, before slicing and serving.