As broke as piecrust
AS BROKE AS PIECRUST - Poor, without money. My husband heard this on a National Public Radio program (October 2002) about rhythm and blues musicians in the 1940s in Los Angeles. "We were as broke as piecrust." Piecrust is very delicate and crumbles easily.
Another piecrust phrase is 'piecrust promises' -promises that have been made to be broken.