1. Preheat oven to 350°F. Coat a 9-inch baking pan with nonstick cooking spray.
2. In a colander, drain and rinse beans.
3. In a large bowl, whisk eggs, oil and vanilla with a fork. Add beans and mash with fork until beans are barely visible (this can take 5 or more minutes of mashing). Stir sugar and cocoa, and blend with a rubber spatula until mixed. Stir in chips or nuts if using.
4. Pour the batter into the baking pan. Bake until a knife inserted in the center of the brownies comes out clean, 25 to 30 minutes. Let cool completely before cutting into 16 squares.
- Nonstick cooking spray
- 1 (15-ounce) can black beans or 1 3/4 cups cooked, cooled black beans
- 3 large eggs
- 3 tablespoons canola oil
- 1 teaspoon vanilla extract
- 1/2 cup packed brown sugar
- 1/3 cup cocoa powder