[heurisko]

Biscuit - "twice baked" in French.

[periheli0n]

That would then be „Zwieback“ in German, which refers to a kind of crispy mildly sweet bread that children get fed when they are ill :)

[maxnoe]

Or Doppelback, a break type

[oblio]

This is one of those facepalm moments :-))