Did you mix as per the recipe; or did you have to sub ingredients?
I find it vapeable after just a couple of days (though it does get better with more time). And, like Fran, I never got any sort of defined custard, or pudding note. I know it is there... but it lends more "body" and a tad of moistness, to an otherwise kinda dry "one-note" cookie.
If it is that pronounced, to your palate; maybe, try reducing the custard by 0.5%, and halving (or even completely) omitting the vanilla shisha. (If you do try this; start with a small batch. You may prefer the original more.

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