I was making cornbread and needed to share it with a lactose-intolerant friend. I had no oil in the house and my recipe called for a lot of butter and milk. I tried a new substitute for butter and it worked great!
I cooked white beans, mashed them up, and substituted them for butter. You use the same quantity. If you're using canned beans, rinse them first to get rid of some salt. Note: This works well in cakes and brownies, supposedly, but not cookies.
The cornbread turned out fine, although if I do it again, I'll add salt to the recipe. The flavor wasn't as good without butter OR milk (I just put water).