Deal with nice surprise (5)
I believe the answer is:
treat
This clue is a double definition.
'deal with' is the first definition.
(synonyms)
'nice surprise' is the second definition.
(I've seen this before)
(Other definitions for treat that I've seen before include "Nurse" , "Handle - pleasure given" , "An indulgence; handle" , "pay for another" , "Care for medically" .)