Beheld undecorated cake (7)
I believe the answer is:
noticed
'beheld undecorated cake' is the definition.
The answer and definition can be both to do with perception as well as being past participle verbs.
Maybe there's an association between them I don't understand?
'cake' is the wordplay.
I cannot really 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 found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for noticed that I've seen before include "Realised" , "Observed or saw" , "Detected" , "Marked" , "Became aware of" .)