Handle a nice surprise (5)
I believe the answer is:
treat
This clue is a double definition.
'handle' is the first definition.
(synonyms)
'a nice surprise' is the second definition.
(I've seen this before)
(Other definitions for treat that I've seen before include "Practise medicine" , "Pay for - minister to - deal with" , "Nurse" , "Source of gratification" , "Care for - pay the bill" .)