Mix the egg whites
Preheat the oven to 165 degrees. Line a sheet measuring 35×25 cm with baking paper. In a large bowl, pour the egg whites and mix them until they form into soft snow, about 3 minutes. Gradually add sugar while constantly mixing until stiff snow is formed.
Add the dry ingredients
Turn off the mixer and add the dry ingredients. Combine with a spatula and pour the mixture into the prepared tin. Level the surface with a spatula.
Bake a biscuit
Transfer the biscuit tin to the oven and bake for 25 minutes. Remove from the oven and let cool.
