In large bowl, mix all dry ingredients (flour, baking powder & salt).
In separate large bowl, mix flaxseed mixture, sweet potato, yogurt, oil, milk, syrup & vanilla.
Add wet ingredients to dry ingredients and mix until moistened and thick.
Drop batter onto hot waffle iron and cook as directed for your particular waffle maker. (May need to do this in batches, keep done waffles warm in oven that has been preheated, then turned off).
Top with desired toppings and serve immediately
Nutrition Info Per Serving (waffle only): Calories 637.3 Total Fat 32.8 g Saturated Fat 4.0 g Polyunsaturated Fat 10.4 g Monounsaturated Fat 16.9 g Cholesterol 0.0 mg Sodium 688.1 mg Potassium 576.2 mg Total Carbohydrate 79.2 g Dietary Fiber 6.6 g Sugars 21.1 g Protein 8.9 g