1/3 cup vegetable oil 1 cup all-purpose flour 1/3 cup granulated sugar 2 eggs 3/4 teaspoon baking powder 1/4 teaspoon salt 1/2 teaspoon vanilla extract 1/4 teaspoon baking soda 1/2 cup Amish Friendship starter 2 bananas, mashed 1/2 cup chopped nuts