The description of a punchbowl waterfall sounds like several of the waterfalls at Watkins Glen. The plunge has carved out a deep bowl in the rock underneath the falls.
This punchbowl falls term could also describe the Horseshoe Falls at Niagara Falls and the High Falls at Rochester. In both cases, the pool under the falls is deeper than the height of the falls. These could also be described as plunge falls and block falls.
Thanks for the article.