Preheat your waffle iron according to the manufacturer’s directions.
In a large bowl, place the flour blend, xanthan gum, cornstarch, baking powder, baking soda, and salt, and whisk to combine. Add the crisp rice cereal and mix to combine.
In a separate small bowl or 2 cup+ measuring cup, place the milk, oil, and egg yolks, and whisk to combine well.
Create a well in the center of the dry ingredients, add the milk mixture, and mix to combine.
Place the egg white in another clean, medium-size bowl, and beat with a handheld mixer on medium speed just until soft peaks form.
Add the whipped egg white to the rest of the waffle batter in two batches, and fold in using a silicone spatula until no more than a few white streaks remain.
Open the preheated waffle iron, and pour about 3/4 cup to 1 cup of batter on the waffle iron, depending upon the size of the waffle iron.
Aim to fill the bottom wells of the iron in a single layer nearly to the top. Working quickly, spread the batter into an even layer.
Close and secure the lid, and allow the waffle to cook for about 4 minutes or until steam has largely stopped escaping from the iron. Open the iron, remove the waffle using tongs, and place on a wire rack to cool.
Repeat with the remaining waffle batter.
The cooked waffles can be served right away or cooled completely, wrapped tightly and frozen. To refresh from frozen, defrost and warm in a toaster oven at 300°F or in a toaster on medium. Serve immediately.