The Germanic languages have the ability to form compound nouns (composita). German is notorious for that, and the Scandinavian languages like to do so as well.
Nowadays, English has a tendency to write words separately, but there are still many examples of composita in English as they are quite common: e.g. noun + noun: firefighter, boyfriend; adjective + noun: redhead, greenhouse.
Favorittforfatter is such a latter case of adjective + noun in Norwegian (I think? it might be noun + noun), while Lieblingsautor in German is an example for noun + noun.