No it’s not.
“The proof is in the pudding” sounds like some sort of chemical test used by TV-show forensic detectives. “We must test for the presence of poly-tapioca-morphus, which will prove the culprit is actually Bill Cosby! Apply the pudding!”
That’s one of the problems with cliches, beyond lack of creative thought and simple boring overuse. Some of them, if you stop to think about them, make absolutely no sense.
No, “The proof of the pudding is in the eating.” Doesn’t matter if it appears delicious, or jiggles firmly when you shake the bowl. The true purpose of the subject in question—in this case, taste and nutrition of the food consumed—is all that ultimately matters. Not that I’m encouraging using such overwrought phrases, but one can actually freshen this cliche by returning it to its original phrasing. We’re so conditioned to the misuse of this hoary phrase that proper quotation will illuminate and enliven it. In that sense, the proof is in the putting, and the putting is in the reading: putting all the words in, and in the right order.