Money? Some people like jam on it! (5)
I believe the answer is:
bread
'money?' is the definition.
(bread is slang for money)
'some people like jam on it' is the wordplay.
I cannot really understand how this works, but
'some' could be 'a' and 'a' is present in the answer.
'on' could be 're' ('on' can be mean 'with reference to') and 're' is located in 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 bread that I've seen before include "Dosh (slang)" , "Eg, pumpernickel" , "Staple food" , "Loaf; money" , "Foodstuff; money" .)