1. Coat a nonstick waffle iron with cooking spray. Preheat according to the manufacturer's directions.
2. Place the egg whites in a mixing bowl and beat on high until stiff peaks form.
3. Whisk together the flour, baking powder, baking soda, cinnamon, and salt in a medium bowl. Whisk in the soy milk, pumpkin, honey, oil, and vanilla just until blended. Gently fold in the egg whites until just combined.
4. Spoon ½ cup of batter on the bottom grids, covering two-thirds of the grids. Close the iron and bake according to the manufacturer's directions
5. Using a rubber spatula, carefully remove the waffle from the iron. Repeat with the remaining batter.
NOTE: Ingredients for a changed serving size are based on a calculation and are not reviewed by the author or tested. Please also consider scaling up or down cooking containers as needed.