Source: Victory Garden - 11-3-99

1 1/2 pounds sweet potatoes, peeled,
    cooked and pureed to equal 2 cups
1 1/2 cups vegetable oil
4 eggs
1 teaspoon vanilla extract
3 cups all-purpose flour
1 1/2 cups granulated sugar
2 teaspoons baking powder
2 teaspoons baking soda
2 teaspoons cinnamon
1/2 teaspoon ginger
1/4 teaspoon cloves
1/4 teaspoon nutmeg
1 teaspoon salt
1 cup chopped nuts
1/4 cup melted chocolate

Combine potatoes, oil, eggs and vanilla extract. Add slowly the dry ingredients that have been mixed together. Fold in the nuts. Mix chocolate with 1/3 of batter. Pour some batter in a greased 9 x 13-inch pan and swirl chocolate batter in to give it a marbleized effect. Add remaining batter. Bake at 350 degrees F for 1 hour 10 minutes.