Sweet potato: 150g (1 medium, cooked and mashed), Whole wheat flour: 60g (1/2 cup), Baking powder: 4g (1 tsp), Cinnamon: 2g (1/2 tsp), Nutmeg: 1g (1/4 tsp), Salt: 1g (1/4 tsp), Egg: 50g (1 large), Milk (1% fat): 60ml (1/4 cup), Vanilla extract: 2ml (1/2 tsp), Maple syrup: 10ml (2 tsp), Walnuts: 15g (2 tbsp, chopped, for topping), Olive oil: 5ml (1 tsp for cooking)