What is the best substitute for butter?

Unsweetened Applesauce: This fruit puree mimics butter's richness, moisture, and texture, making it an ideal sub for baking. Use cup-for-cup measurements, but it's best to use it in recipes calling for melted butter. 

Plain Greek Yogurt: This tangy dairy also keeps batters moist, adds extra protein and flavor, and lowers cholesterol. Use half yogurt to half butter in baked recipes; this is our pick if you're avoiding oil altogether. 

Mashed Avocado: Creamy, subtly nutty, and good for you to boot, use the same amount of mashed avocado as you would butter in baking. It works especially well in chocolate baked goods. 

Coconut Oil: This tropical fat is a great non-dairy option that imparts some faint sweetness. Use cup-for-cup. It's especially great for fudgy textures in cookies and brownies, and flaky pie crusts. Because coconut oil is a hard fat, it does harden when cold.

Olive Oil: Use a light variety; it's best suited to baking when a recipe uses a lot of other flavorful ingredients (chocolate and cocoa, bananas and nuts). Use cup-for-cup with light varieties, but use less when the olive oil flavor can be overpowering.