In English we call it "Marshmallow".

In Icelandic it’s sykurpúði = sugar cushion 😄

In Danish it's skumfidus which means foam thingie.

I'm German and that is bullshit. Never heard of mäusespeck, everyone just calls them marshmallows and they are labeled as marshmallows in the store

EDIT: I was made aware that the Problem seems be that im not a boomer. 30 years ago, when i wasnt alive, they seemed to be called this. In my WG there are people over 30 though and they also never heard of this (hessen)

In Finnish it's 'vaahtokarkki' which translates to foamcandy.

We call it 棉花糖 in Chinese, which translates to cotton candy... Which gets confusing if we're also talking about cotton candy (the fluffy kind).

In Dutch it's also marshmallows, but also commonly spek (bacon), spekjes (bacon pieces) or spekkies (in this case it's clear you're not talking about bacon).

I’m pretty sure alot of languages just imported marshmallow.

I come from the german speaking part of Switzerland and I don’t think I ever heard someone actually use the word “Mäusespeck” although it certainly would he understood I think. Everybody around me calls them marshmallows.

Malvavisco (Spanish).

In Polish we call them pianka, diminutive for foam

Nein, davon weiß ich absolut nichts. Das ist regional allerhöchstens oder ein Synonym für Marshmallow.

Skumfidus 🇩🇰

"Foam trick" i guess, is the literal translation.

Fidus is a weird word.

Schaumzucker (German), literally "foam sugar"

We didn't bother translating, so it's marshmallow. Sometimes written phonetically, maršmelou.

Guimauve

Here in Mexico (Spanish) is known as Bombón. A quick Google search says that apparently comes from the repetition of the french word 'bon'

It is worth to mention that, despite most of the countries in Latin America speak Spanish, things have different names in different countries, even if it's the same language.

According to Wikipedia, marshmallows are also known as

nube,​ esponjita, malvavisco, fringuel, jamón o suncho

Never heard of that in German. It's just marshmallows with a generic German accent instead. But it's cool to learn something new. Which region says that, OP?

In Norwegian marshmallow is just marshmallow, but if something has marshmallow bits or marshmallow like properties (like say the white stuff in a bag of Haribos) it's called "skum", which means foam

Guimauve or Purple mistletoe for whatever reason.

Malvaviscos. En español.

žužu in Czech (ž as the first sound in Zhukov), but it's often called marshmallow as well (especially the iconic/most common form).

מרשמלו

My native language is German but I lived in Spain for a long time and there they call them "nubes", clouds.