Cooking pot: spoil little one (7)
I believe the answer is:
marmite
'cooking pot' is the definition.
(type of cooking pot)
'spoil little one' is the wordplay.
'spoil' becomes 'mar' (synonyms).
'little one' becomes 'mite' (I've seen this in another clue).
'mar'+'mite'='MARMITE'
(Other definitions for marmite that I've seen before include "Savoury spread (which you either like or you don't)" , "polarising response" .)