I fried donuts in lard once on a whim, and boy let me tell you what that kicked it up a notch. The butter filled brioche fried in pig fat was glorious. Back in the day when lard was cheap that would make sense on a production level, but was cost prohibitive otherwise. That lard batch was maybe the best ever donuts in history.
We did make vegan donuts with Crisco. I didn’t eat that stuff, so I didn’t care.
Chicken fried in bacon grease!