If you’re in the UK/Europe, the best alternative I’ve found are Bahlsen’s Milk Dark Chocolate Leibniz.

Still has the issue of what is this branded product really though.

I think another option is chocolate 'malted milk' (in the UK) - depending on your preference for ratio of biscuit to chocolate to marshmallow. Leibniz will have more/thicker chocolate, but malted milk will break a bit easier in the mouth (softer/crumblier biscuit).

Digestives are a bit thicker, but the ones I had while over there weren't substantially so. You're less likely to get the shared experience of dealing with the goopy mess all over your fingers because your graham is shattering at the first bite.

Well also that you can buy graham cracker crumbs, for making things like pie crusts. My friend gave me a weird look when we went shopping and I picked up whole crackers. And then the revelation that graham refers to a type of flour and is not in itself a brand. And Kelloggs sell the crumbs? Wild.

A biscuit base in the UK would usually require a pack of digestives and a rolling pin. I suppose some supermarket sells crumbled biscuits but...

As an aside, Golden Grahams used to be popular in the UK and I don't think anyone stopped to ask what the name meant.

Golden Grahams is popular in France too, but as a foreign name, nobody ever looked it up.

Digestives actually is a pretty good sub! Yeah theyre thicker but I think the most substantial difference is that graham crackers are significantly harder and less crumbly.