1 1/8 cups packed brown sugar
1/2 cup canola oil
1 teaspoon vanilla extract
2 eggs
2 cups all-purpose flour
2 teaspoons baking powder
1 teaspoon ground cinnamon
1 teaspoon freshly grated nutmeg
1/2 teaspoon ground allspice
1/2 teaspoon salt
4 cups peeled, shredded sweet potato
1/2 cup raisins
1 cup walnuts