Growing up in Germany nowadays Peanut Butter is an option, but way more popular is Nutella. But that contains peanuts too! 13% according to the Nutella website and some of the peanuts are sourced from the USA. So given the peanut fungi hypothesis, why would peanut butter (rarely) cause the allergy and not Nutella? (higher peanut concentration?)

(german) source: https://www.nutella.com/de/de/entdecke-nutella/faqs#haseln%C...

There are no peanuts in Nutella - the very page you link to shows hazelnuts, which is also what it says on the actual Nutella label: Haselnüsse (13%)

Isn’t it hazelnut in Nutella ? These are way more common in Europe (as walnuts are). Usually in France, traces of peanuts are reported in the composition of product, but only because production lines in the same factory might deal with peanuts.