4 egg whites
200 gr flour
150 gr potato starch (fecola di patate. In american grocery store it's difficult to find and I buy mine at www.supermarketitaly.com)
1 tsp baking powder
150 gr sugar
4 tbsp of butter or peanut oil or vegetable oil. Remember that soy and corn in the United States are genetically modified unless it says ORGANIC USDA on the label.
orange zest (I used a mandarin instead and it made it smell very good)
Oven set on 170 C or 300/325 F
For the step by step enjoy the video!