|1. Preheat a waffle iron.
2. In a large bowl, with a handheld electric mixer set on medium, beat together the eggs, flour, oil, sugar, baking powder, salt, vanilla and pumpkin pie spice. When the batter is smooth, stir in mashed sweet potatoes.
3. Spray the waffle iron with the nonstick cooking spray. Pour approximately 3/4 to 1 cup of the batter into the center of the waffle iron, then close the top. Follow the instructions for your waffle iron, baking the waffles until they are crisp and hot.
4. Remove the waffles from the waffle iron; repeat this process with the remaining batter: Serve hot w. syrup, if desired.