I'm just wondering because I have never heard of this before. Are you able to taste the apple sauce or is it tasteless like vegetable/olive oil in cakes (well to me I can't taste it). Please share with me 
Can you only substitute apple sauce for certain types of cakes?
If the recipe calls for 1 cup of oil would I use 1 cup of apple sauce?

Can you only substitute apple sauce for certain types of cakes?
If the recipe calls for 1 cup of oil would I use 1 cup of apple sauce?