"flat as a fritter"

I've often heard "flat as a fritter" to explain how flat something is. Is "fritter" a pancake or does it refer to something else?

Pancake. There are lots of other things called fritters that are not quite as flat, and there are lots of other names for pancakes but that don't alliterate with flat.
SS

Kansas, Dorothy's home before and after visiting Oz, is often referred to as "flat as a pancake." Some scientists did a study (one can only hope it was not tax-funded) that conclusively proved that it was even flatter. If you were to enlarge a pancake to the size of Kansas, it would have ups and downs and holes and such, and be much more rugged to cross. Food for thought. One would think that a fritter, which by definition has lumpy bits added into the batter, would be positively mountainous by comparison. Unrelated topographical note: if the earth were reduced to the size of a billiard ball, it would be smoother than a billiard ball. So there.