Preheat oven to 350 degrees. Spray a 9x5 loaf pan (or mini loaf pans) with cooking spray. Set aside.
In a large mixing bowl, mash sweet potatoes in 2 tablespoons of liquid.
Add sugar, water, oil, and eggs to mashed sweet potatoes and mix well.
Add flour, baking soda, salt, nutmeg, cinnamon and allspice, and baking powder. Mix well.
Stir in chopped pecans.
Pour evenly into prepared pan(s). For the 9x5 pan, bake for 60-70 minutes or until toothpick inserted into center comes out clean.** The smaller loaves will take about 45 minutes to bake.
Cool for 15 minutes in the pan. Turn out onto a wire rack to cool completely.
Store in an airtight container.
*For mini loaves, check the loaves at 30 minutes and add more time as needed. All mini pans are different sizes so it is hard to give an exact time.