Whisk egg, almond flour, and baking powder together in a bowl. Stir in mozzarella cheese; set batter aside.
Preheat a waffle iron according to the manufacturer's instructions.
Spray both sides of the preheated waffle iron with cooking spray. Pour ½ of the batter onto the waffle iron and spread it out from the center with a spoon. Close the waffle maker and cook until chaffle reaches your desired doneness, about 3 minutes. Carefully lift chaffle out of the waffle iron and repeat with remaining batter. Allow chaffles to cool and crisp up, about 2 to 3 minutes.
