Fats in dessert recipes?

Nope, completely different as far as taste, texture, and how fatty it is. You would use the same measurement for all though. For oil- canola would be a healthier option. You can use 3/4 oil and 1/4 butter so you have the butter flavor. Can always substitute applesauce for the the oil/fat. Either substitute all of it or a portion of it. You really can't tell the difference if you're substituting applesauce for oil or shortening. You do have to use some butter to get the butter flavor.