Leave hands to become cracked (2,7)
I believe the answer is:
go bananas
'become cracked' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.
'leave hands' is the wordplay.
'leave' becomes 'go' (to go is to depart or leave).
'hands' becomes 'bananas' (I've seen this before).
'go'+'bananas'='GO BANANAS'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for go bananas that I've seen before include "Lose one's cool" , "Freak out" , "Become mad or furious" , "become very angry" , "Be extremely excited" .)