Step 1

Preheat the oven to 350 degrees F (175 degrees C). Grease a 9-inch round cake pan.

Step 2

Place the chocolate chips into 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 the power to 50 percent.

Step 3

Combine the beans and eggs in the bowl of 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 chocolate is completely mixed. Transfer the batter to the prepared cake pan.

Step 4

Bake for 40 minutes in the preheated oven, or until a knife inserted into the center of the cake comes out clean. Cool in the pan on a wire rack for 10 to 15 minutes before inverting onto a serving plate. Dust with confectioners' sugar just before serving.