Preheat oven to 325 degrees F (160 C)
Separate eggs and place egg whites into a stand mixer bowl.
In a separate bowl using a sifter place cornstarch, white rice flour, tapioca flour, salt, and ¾ cup (150 g) sugar. sift and set aside.
In a small bowl measure extracts and put aside.
Using the wire whisk attachment beat egg whites on high speed until they start to come together ad cream of tartar.
When egg whites form soft peaks turn speed down and ad extracts, turn speed back up and slowly add ½ cup (100 g) sugar in a steady but slow stream.
Beat until stiff peaks are formed.
Remove bowl and fold dry mixture in one large spoonful at a time careful not to deflate your egg whites.
Place mixture into ungreased angel food cake pan and bake for approx. 55-60 minutes.
When cake is done, remove from the oven and turn upside down on a cup or bottle and cool completely before removing from the pan.