Swapping olive oil for some or all fats, like butter, lard, shortening and margarine, in your baking, is a simple way to cut down on bad cholesterol and calories. As a bonus, the switch will also add antioxidants and vitamin E, which will help keep your muffins and breads fresher longer while adding a bit of extra moisture. The golden rule when substituting extra virgin olive oil for butter is to use 3 tablespoons of oil for every 1/4 cup of butter.