Handle with unusual pleasure (5)
I believe the answer is:
treat
'handle' is the definition.
(synonyms)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for treat that I've seen before include "Alternative to trick" , "Entertain and pick up the tab" , "Delightful outing; pay for (someone else)" , "could be a feast" , "Give care to; surprise gift" .)