The choices are endless. Not only are you reducing saturated fats in your baked goods, the multiple choices in Olive Oil can change the flavor profile of bread, scones,cookies, pies muffins or cakes in an instant.
The oil you choose, should enhance the flavor of the recipe, therefore, use only good quality extra virgin olive oil. Flavored olive oils can add interest to your baked goods. Fruity flavors for sweet treats, and herb or garlic for breads and other savory recipes.
For recipes that include a vegetable oil, replace it with the same amount of olive oil. The ratio would be 1 to 1. When substituting butter the ratio is 4 to 3. One cup butter = 3/4c olive oil.
Keep in mind, olive oil can not be substituted in all recipes calling for butter. For example, your mother's favorite short bread cookie recipe, cake frostings (frostings or anything that must stay solid at room temperature, and shortbreads, cuz mom would haunt me),