Preheat oven to 325 F. Line 8 inch square baking pan with parchment paper, and set aside.
In food processor, place beans and eggs, and blend until very smooth. Add sugar, milk powder, cornstarch, baking powder, and salt and blend together. Place cubes of softened butter, vanilla, and orange zest into food processor container and blend until you only see small pebble sizes of butter.
Place mixture into prepared pan and sprinkle on half of chocolate chips. Bake in preheated oven for 15 minutes. Sprinkle on remaining chocolate chips and bake for another 25 minutes, or until a tester inserted into the centre comes out clean.
Allow to cool for at least 10 minutes before lifting blondies out of pan and cooling completely on wire rack. Slice into 9 equal pieces. Store any leftovers in a tightly sealed container in the refrigerator for up to 1 week, or in the freezer for longer.
Recipe Notes
Per serving: 272 calories; 10 g protein; 12 g total fat (7 g sat. fat); 33 g total carbohydrates (5 g sugars, 2 g fiber); 183 mg sodium