"Anko" is a collquial expression for "an".First, in hiragana, it says "an" (あん), when I Look this up it says it is 餡
or red bean paste. But isn't it really "anko" not "an"? Why was it shortened?
The second part says doonatsu, or donut.
"Anko" is a collquial expression for "an".
So "an" is not a shortened version of anko, but "ko" is an addition to "an".
And yes, it means donuts.
It's a "fusion" of donuts and Japanese "an" - I love an-doonatsu, yum!
SL language or words that are colloquial are used mainly in informal conversations rather than in writing or formal speech