Yes. In the Netherlands, psilocybin mushrooms are banned since 2008, but psilocybin truffles are legal and are used in guided truffle ceremonies and retreats.
German-language guidance is available. You can join a group retreat or book a private one-on-one session, typically hosted in practice rooms, rented venues, hotels, or quiet nature settings.
A typical format includes preparation and intake, a 4 to 6 hour truffle session, and an integration conversation afterward. Some retreats are all-inclusive, covering guidance, meals, drinks, and sometimes lodging.
For current German-language dates and booking options, see this page. Hope that helps.