100% spit cooking. The bit on the left screws into the rotating part. The other two pieces slide onto the shaft and are meant to hold the meat in place.
Definitely looks like a Klingon sex device though.
I used to remove this from my mom's oven, adjust the spikes and pretend they were a sword ward. She didn't roast many chickens in the oven so never scolded me :)
Yeah, not sure what kind one that size is but my air fryer has the same type of getup for toasting chickens on a smaller scale. Probably threaded into a motor on the one end to keep it spinning.