Preheat the oven to 350°F (180°C), or 160°C for a fan oven. Line a 9×5 inch (approx 23x13 cm) loaf pan with parchment paper.
In a large bowl, whisk together the sugars, eggs, oil, water, vanilla extract, and the mashed sweet potato.
In a separate bowl, combine the dry ingredients (flour, baking soda, salt, cinnamon, and nutmeg).
Add the dry ingredients to the wet ingredients, mix until there are no dry patches of flour but do not over mix (this is very important).
Fold in the chopped pecans.
Place the loaf pan in the oven and bake for approximately 50-60 minutes, or until a toothpick inserted in the center comes out clean or with a few moist crumbs.
Allow the sweet potato bread to cool completely on a rack before removing from the pan and serving.