Peel and slice potatoes and place in a 9-by-13-inch baking dish.
Add water, sugar, and sprinkle with spice of your choice. Place 1 stick of margarine pats on top of potatos, add pecans (if you're using them).
Sprinkle dry cake mix on top of potatoes and add remaining stick of margarine pats.
Bake at 250 to 275 degrees for about 1 hour, then increase temperature to 350 until brown.
(Diabetics can use ½ cup Splenda, ¼ cup Splenda brown sugar blend and sugar-free classic yellow cake mix.)