The abundance of sweet treats offered around holidays and special occasions makes it difficult for the calorie conscious to indulge, but substituting applesauce for fats greatly reduces the calorie count. Baked goods use fats -- usually butter or oil -- to make the finished treat rich and tender. Fats also coat the flour to keep the cake fluffy. Applesauce makes the finished cake a bit sweeter and softer than oil, but you don't taste the apples.
The applesauce substitution works best in cake and bread recipes that call for oil, but doesn't work as well in place of butter. While you can substitute for butter in cake recipes with only slight texture change, applesauce doesn't work well as a substitution in cookies because it makes crispy cookies soft and fluffy. The substitution is nearly unnoticeable in dense breads and fruit breads like banana nut or zucchini bread. Use unsweetened applesauce or you risk making the cake too sweet.
Substitute for oil at a 1 to 1 ratio, using 1 cup of applesauce for 1 cup of oil. If you prefer to adjust your palate, substitute only part of the oil and work your way up to total substitution. For example, if a recipe calls for 1 cup of oil, use 1/4 cup of applesauce and 3/4 cup of oil. The next time you bake, use half applesauce and half oil, increasing the applesauce even more the third time until you until you use 1 cup of applesauce and no oil.