sokerina pohjalla

Etymology
The saying dates back to the times when loaf sugar was widely used. That type of sugar does not dissolve easily, and thus some undissolved sugar often remained at the bottom of a cup of coffee after it was drunk.

Adverb

 * 1)  as the icing on the cake, the cherry on the cake, the cherry on top something that intensifies the appreciation of something already good

Usage notes

 * Notice the difference in parsing: is a phrasal adverb whereas "icing on the cake" is a phrasal noun,