Preheat oven to 135 degrees C. Line 2 baking trays with baking paper.
Beat egg whites and sugar in large bowl until soft and creamy, about 2 minutes. Stir 2 cups shredded coconut and gluten-free flour slowly into the mixture until combined into a dough.
Shape dough into walnut-size balls. Roll in the remaining shredded coconut and place 5cm apart on the baking trays.
Bake in the preheated oven until lightly golden, about 30 minutes. Cool on the baking tray for 2 minutes before removing to a wire rack to cool completely.