Fruit purees in place of fats provide enough moisture to bind the mixture and keep the cake from drying out. Plain applesauce is an easy substitute, but use just about any type of fruit puree cup for cup in a cake mix recipe. Keep in mind that the texture of the cake may be slightly denser than if you used oil, and the stronger the fruit flavor, the more noticeable it might be in your cake. To guarantee a moist cake, substitute 1 cup fruit puree and 1 to 2 tablespoons of canola oil for every 1 cup of vegetable oil in the recipe.

Vegetable purees are similar to fruit purees as substitutes for vegetable oil in a cake mix. Stick with purees such as pumpkin, squash and sweet potato because of their neutral flavors and moisture content. You might still notice the flavor of these vegetables in your cake, so use them with a spiced cake or other cake flavor that pairs well. Use ¾ cup of vegetable puree for every 1 cup of oil, and add a few more tablespoons of puree if your batter looks too dry.

Melt butter and add it cup for cup in place of vegetable oil in your cake mix recipe. Butter adds richness to a cake mix and can make it slightly denser. Use butter when you’ll be stacking cake layers or covering them with a heavy icing.

Add fat-free dairy products in place of vegetable oil to give your cake moisture without the fat. Products such as fat-free yogurt or sour cream are suitable replacements, but they may leave your baked cake denser than if you used oil. Substitute ¾ cup of yogurt or sour cream for every 1 cup of vegetable oil. If your batter is too dry, add 1 to 2 tablespoons more.