To cut the fat in your next muffin recipe, replace some or all of the oil with applesauce. This substitution works best in dense, heavy muffins -- such as carrot or spice. You may need to alter your baking techniques slightly to account for the ingredient change.

Use half to three-quarters as much applesauce as oil called for in a muffin recipe. So, if you need a cup of oil, you'll use 1/2 to 3/4 cup of applesauce instead. If you want to minimize the impact on the taste and texture of the final product, substitute applesauce for just a third or half of the oil. In this case, if a recipe calls for a cup of oil, you'd use 1/2 cup of oil and 1/4 cup applesauce. Applesauce can also substitute for some or most of another fat, such as melted butter, in a muffin recipe.

Follow your muffin recipe, leaving out the oil, and add the applesauce with other wet ingredients. Use unsweetened applesauce if possible, so you don't have to adjust the recipe further. If you do use sweetened applesauce, reduce the amount of sugar in the recipe. How much you reduce the sugar is a matter of personal taste.

A muffin made with applesauce instead of oil may turn out denser and heavier. If you don't mind, there's no need to adjust the muffin recipe. If you want to maintain a lighter texture to your muffins, though, use pastry or cake flour in lieu of all-purpose. You could also separate the eggs and beat the egg whites into foamy peaks and fold them in at the end of the mixing process to add lift to the batter. Applesauce will also make your muffins brown more quickly and shorten baking times. Start checking the muffins for doneness about 10 minutes before the recipe says they should be pulled from the oven. Test with a toothpick every few minutes and when it comes out clean, remove the muffins from the oven.

In recipes that call for creaming butter and sugar together as one of the first steps, you're better off not using applesauce as a substitute. This process creates small air pockets that contribute to a light, tender muffin. Examples of muffins that might incorporate this process and be less successful with applesauce as an oil substitute are blueberry and lemon poppy seed. If you still want to reduce the fat content in these creamed recipes, eliminate the egg yolks in the recipe and use two egg whites for every egg required.