Preheat your oven to 350°F (175°C). Grease and flour a 9x13-inch baking pan.

If you haven't already, cook your sweet potatoes until tender. Allow them to cool, then mash until smooth.

In a bowl, combine the flour, baking powder, baking soda, cinnamon, nutmeg, and salt. Set aside.

In a separate, large mixing bowl, beat together the sugar, oil, and eggs until well combined. Add the mashed sweet potatoes and mix until smooth.

Gradually fold the dry ingredients into the wet mixture until just combined. Gently stir in the pecans.

Pour the batter into the prepared pan and spread evenly. Bake for 30-35 minutes, or until a toothpick comes out clean.

While the cake is baking, combine the brown sugar and a tablespoon of water in a small saucepan over medium heat. Stir until the sugar dissolves.

Once the cake is done, take it out of the oven and immediately pour the glaze over the hot cake, allowing it to soak in.

Let the cake cool before slicing. Serve it warm or at room temperature.