To make the syrup, in a saucepan, combine the blueberries, water (if using), lemon juice and zest, honey, 1 tablespoon molasses, and cloves. Bring to a boil over medium-high heat, then reduce the heat to low, cover and simmer until the berries burst and the juices are slightly thickened, about 5 minutes. Frozen berries may take slightly longer to thicken. Set aside and keep warm.
If using sweet potatoes, bring a small saucepan half full of water to a boil. Add the sweet potatoes, return to a boil, then reduce the heat to medium low and simmer until very tender, about 10 minutes. Drain and puree in a food processor or mash with a potato masher until smooth. Set aside. If using pumpkin puree, reserve.
In a small bowl, sift together the flours, cornmeal, baking powder, salt, cinnamon and ginger. In a large bowl, whisk together the soy milk, sweet potato puree, olive oil and 2 tablespoons molasses. Add the flour mixture and stir just until combined.
Using an electric mixer on high speed, beat the egg white until stiff peaks form. Make sure that the mixing bowl and beaters are spotlessly clean and free of fat. Even a small amount of fat, such as egg yolk or oil, can prevent the egg whites from whipping properly. Once whipped, gently whisk 1/3 of the egg white into the batter to lighten it. Using a rubber spatula, gently fold the remaining egg white into the batter, mixing just until incorporated.
Place a baking sheet in the oven and preheat to 225 F. Preheat a waffle iron. Spoon or ladle about 1/2 cup batter into the waffle iron, depending on the size of the iron. Spread evenly and cook according to the manufacturer's instructions. If the batter thickens, thin with a little soy milk. Transfer the waffle to the baking sheet in the oven to keep warm. Repeat with the remaining batter to make 6 waffles. Serve topped with the syrup.