Preheat oven to 350oF (180oC).
Cut chocolate into small pieces. Transfer to a microwave safe bowl. Add oil.Microwave, power 1200W, for 20 seconds. Stir.Microwave for an additional 10-20 seconds until chocolate has melted.PLEASE, note that all microwave oven are not the same. Adjust cooking time according to your oven. To the same bowl, add sugar and water. Stir.
Then, sift in flour and baking powder. Mix.
Bake in preheated oven to 350oF (180oC), rack middle position, 15 minutes
Let cookies cool down on pan for 10 minutes. Then transfer to wire rack to cool down completely.