Preheat the oven to 350°F and grease an 8-inch square baking pan.
Using a food processor, blend together the beans, sugar, eggs, vegetable oil, cocoa, vanilla, coffee, baking powder, and salt until the batter is completely smooth. Using a spatula, fold in the chocolate chips and nuts and pour evenly into the greased pan. Bake for 30 to 35 minutes, until set in the middle and the edges begin to pull away from the sides of the pan. Remove from the oven and allow to cool completely before cutting into bars. The brownies can be stored in an airtight container in the refrigerator for up to 1 week.