In most recipes, olive oil can be substituted for butter at a 3:4 ratio by volume.
For example, if the recipe calls for 1 cup (225 grams) of butter, you can replace it with 3/4 cups (180 ml) of olive oil.
Since olive oil is a liquid, it’s not a proper butter substitute in recipes that need the fat to remain solid or that require a lot of creaming, such as frosting and angel food cake.
Olive oil’s strong flavor works well in recipes that have a fruity, nutty, or savory quality, such as pumpkin bread or muffins.
Using olive oil cuts down on "bad" cholesterol and saturated fat in your baking. It's considered a "good" fat, unlike butter. It also adds extra antioxidants (natural chemicals that help protect our cells) and vitamin E to your baked goods, giving your desserts a heart-healthy boost.