Purpose of Oil

• Many baking recipes call for vegetable oil. Oil serves a purpose in baking but it can be replaced, so long as you know why it is being used in the first place. Adding oil to your brownies gives them moisture as well as tenderness. The oil cloaks the proteins in the flour, which creates a moist brownie because it prevents water from sticking to the flour and creating gluten. Gluten is a key component to making bread but is not what you want in your brownies.

Go Bananas

• Bananas are frequently used in baking, and not just for banana bread or muffins. Use ripe bananas to create brownies that are more tender and moist. Over ripe bananas — those that have brown spots on the banana peel, puree and blend easier and contribute a natural sweetness to your brownie recipe. Because bananas have that natural sweetness, you'll want to reduce the amount of sugar in your brownie recipe by half, though it can be replaced one for one. One cup of pureed banana equals one cup of refined white sugar.

Making the Switch

• Eliminate the oil from your brownie recipe altogether by using mashed ripe bananas. For every one cup of oil required in your recipe, substitute 3/4 of a cup mashed bananas. Since bananas are low-fat and a better alternative to refined sugar, reduce the baking time on your brownies by about five minutes. Low-fat and low-sugar recipes tend to cook quicker than their full-fat, sugar-laden cousins.

Food For Thought

• Bananas are not the only fruit that can be used in place of fat or oil in your brownies. Other alternatives include mashed or pureed avocados, dates, figs, apples, prunes or apricots. Avocados offer a close substitute to oil or fat because the fruit is full of healthy fats and do not have an overpowering taste. Use dates or figs but beware of the added sweetness. Apples and apricots add subtle sweetness while giving your brownies moisture and tenderness. Fruit substitutes are a sneaky way to add fiber and other nutrients to your otherwise sinful dessert.