Otto makes a mince tart (5)
I believe the answer is:
attar
'otto' is the definition.
Both the definition and answer are singular nouns.
Perhaps you can see an association between them that I don't see?
'a mince tart' is the wordplay.
'mince' indicates anagramming the letters.
'tart' is an anagram of 'ttar'.
'a'+'ttar'='ATTAR'
'makes' is the link.
Can you help me to learn more?
(Other definitions for attar that I've seen before include "Fragrant essence usually associated with the damask rose" , "Fragrant rose oil" , "Fragrant essential oil from damask roses" , "Essential oil from flower" , "Fragrant oil obtained from floweres" .)