Like cake that's plain, perhaps, or spotted (7)
I believe the answer is:
noticed
'spotted' is the definition.
(I've seen this before)
'like cake that's plain perhaps' is the wordplay.
I cannot quite understand how this works, but
'cake' could be 'ice' (I have seen 'Top cake' mean 'ice' so perhaps 'cake' could also mean 'ice') and 'ice' is present in the answer.
This explanation may well be incorrect...
'or' is the link.
Can you help me to learn more?
(Other definitions for noticed that I've seen before include "Seen" , "remarked" , "Marked" , "Realised" , "Detected" .)