It may be a piece of cake (5)
I believe the answer is:
slice
This clue could be a double definition.
'it' is the first definition.
The definition suggests a singular noun which matches the answer.
'be a piece of cake' is the second definition.
(I've seen this in another clue)
'may' is the link.
Can you help me to learn more?
(Other definitions for slice that I've seen before include "shot in golf that goes astray" , "poor golf shot" , "Spin" , "Serving cut from a larger portion" , "Portion of pizza" .)