preheat the oven to 350 degrees F (175 degrees C). Grease a 9-inch round cake pan.
Place the chocolate chips in a microwave-safe bowl. Cook in the microwave for about 2 minutes, stirring every 20 seconds after the first minute, until chocolate is melted and smooth. if you have a powerful microwave reduce power to 50%
Combine the beans and eggs into a food processor. Process until smooth. Add the sugar and the baking powder, and pulse to blend. Pour in the melted chocolate and blend until smooth, scraping down the corners to make sure the chocolate is completely mixed. Transfer the batter to the prepared cake pan.
Bake for 40 minutes in the preheated oven, or until a knife inserted into the center comes out clean. Cool the pan on a wire rack for 10-15 minutes before inverting onto a serving plate. Dust with confectioners' sugar just before serving.