The proprietors (from the Boar's Head) of the newly-moved-to-the-Square café are obviously worldly wise. They have successfully translated 'Coffee House' to the much more chic Germanic 'Kaffeehaus'. Maybe they're after the redolence of Berlin's fashionable Kurfürstendamm. What with the Germanised version of the Manor House, perhaps Leonard Cohen was right with his famous song, 'First we take Llansannan. Then we take Berlin'.
When advertising the Italian-style pressed and grilled sandwich, not only do we see a rogue butcher's apostrophe (but no such intrusion for taco's (sic) or nacho's (sic) though the other bread product, the French word baguettes, regrettably does see one).
Neither their Italian nor their use of English is perhaps as good as their German.
No, there's more. Paninis is of course not the plural. It's just 'panini'. No need for an 's'. The singular is 'panino'. For the sale of panini, we need neither the trailing s nor the apostrophe. But, you knew that, didn't you.
Unless this isn't Kaffeehaus at all but Panini's Café, that is, belonging to some Italian bloke named after a plate of sandwiches.