In a mini food processor, or blender mix egg, milk, spinach or kale and banana until greens are finely shredded.
Pour into remaining ingredients, except chocolate chips. Mix until incorporated, but do not over mix. Stir through chocolate chips.
Pour batter into prepared donut pan. Bake 15 minutes or until a toothpick inserted comes out clean. Remove from the oven and allow to cool for a few minutes before removing from pan.