Take no notice of upside-down cakes from the bakery (4)
I believe the answer is:
snub
'cakes from the bakery' is the definition.
The definition and answer can be both acts as well as being singular nouns.
Maybe there's a link between them I don't understand?
'take no notice of upside-down' is the wordplay.
I cannot really understand how this works, but
'no' could be 'n' (common abbreviation) and 'n' is located in the answer.
The remaining letters 'sub' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for snub that I've seen before include "Slight - short and blunt - humiliation" , "Refuse to acknowledge" , "Rebuff; brush-off" , "Check" , "16" .)