My mom told me you can substitute unsweetened apple sauce for oil in a recipe. I tried that today. I made some experimental whole wheat oatmeal raisin muffins. They actually turned out pretty well. I substituted apple sauce for about 3/4 of the oil and the last 1/4 I used oil. I think they'd taste better with butter on them, but that would defeat the purpose. My daughter likes them because they have raisins in them.
I've learned that if you are substituting ingredients to make something healthier, substitute about 1/2 to 3/4 of the amount and leave the rest what it was supposed to be in the first place. That way, the recipe's taste and texture are a lot closer to what you are expecting.
For example, my recipe called for 1/2 c oil. I instead I added 3/8 cups of apple sauce and 1/8 cup of oil. The easy way to do this is to add 1/4 c apple sauce, fill the 1/4 cup about half full with apple sauce and the rest with oil.