If you want to cut back on shortening or butter in pie crust, use an equal amount of coconut oil. Coconut oil is the only oil that gets to a part of the brain which has a lot to do with Alzheimer's. It also contains medium-chain fatty acids which are metabolism-revving.
You can reduce the fat in brownies by 50% with a simple substitution. Replace half the butter or oil called for in the recipe with an equal amount of pureed prunes or prune baby food. Not only will this reduce the fat, but it will also add heart-healthy potassium.
I personally like to substitute unsweetened applesauce to many of my baked goods.
