For the pancake batter:
Preheat the oven to 350 degrees F. Place the sweet potato pieces and maple syrup into aluminum foil and place in the oven for an hour. When the potato is tender, place the potato pieces and syrup in to a bowl and mash with a fork.
In a large bowl, sift together the bread flour, cake flour, granulated sugar, brown sugar, baking powder, cinnamon, 3/4 teaspoon salt, nutmeg, and ground ginger.
In a separate bowl, whisk together the milk, egg yolks, melted butter, vanilla extract, and mashed sweet potato, then whisk the milk mixture into the sifted dry ingredients. Whisk well to make sure there are no lumps.
Place the egg whites into a separate bowl and whisk to firm peaks. Fold the whipped egg whites into the batter in 3 additions. Let the batter rest for 5 minutes.
Heat a flat top (or large griddle) on medium heat. Spray the pan with a little nonstick cooking spray. Ladle 2-ounces or 1/4 cup of batter into the pan, let cook for 3 to 4 minutes then flip, once brown on both sides remove from pan. Keep warm.
For the citrus brown sugar sauce:
Melt the butter in a medium-size saucepan over medium-low heat. Stir in the light brown sugar.
When the sugar has dissolved and the mixture starts to simmer, add in the zest and the juice from the lime, lemon, and orange. Bring the mixture back to a simmer, stir in the rum and remove from heat.
Stack the pancakes on a plate and spoon the sauce over top and enjoy!
Cook's Note: After the potatoes are roasted mash them with a fork only. This allows there to be pieces of sweet potato in the pancakes. It gives them a nice texture and even better flavor with the other spices in the pancake batter.