Consuming this is a piece of cake in the U.S. (4,4)
I believe the answer is:
duck soup
'consuming this is a piece of cake in the u s' is the definition.
'duck soup' can be an answer for 'is a piece of cake' (I've seen this in another clue). I'm not sure about the remainder of the definition.
'piece of cake in the u s' is the wordplay.
I cannot really see how this works, but
'piece' could be 'p' (abbreviation for Pawn) and 'p' is found in the answer.
'of' could be 'o' and 'o' is found in the answer.
'u' is found in the answer.
's' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for duck soup that I've seen before include "Marx Brothers film" , "From comic film" , "An easy task" , "funny film" , "Classic film" .)