Whatever is at hand. Doesn't matter to me whether it's grape, strawberry, apple butter, etcetera. They normally all taste just fine when paired with peanut butter.
Just looked it up to see exactly what it is and apparently it's just applesauce that's been cooked down for hours until it's thick and spreadable.
I think there are still jars of the stuff from when my sister-in-law made some around the apartment I'm in. Pretty good with peanut butter, if I say so.
Don't know what type of question you were asking, so this is the answer I'm giving.