In essence, a tart can be something fragrant (5)

I believe the answer is:
attar
'in essence' is the definition.
'attar' can be an answer for 'essence' (I've seen this in another clue). I'm unsure of the 'in' bit.
'a tart can be something fragrant' is the wordplay.
'a tart' can be anagrammed to 'ATTAR'.
Though, I am not sure how the anagram is indicated.
Can you help me to learn more?
(Other definitions for attar that I've seen before include "Fragrant oil obtained from roses" , "Fragrant essential oil from damask roses" , "Essential oil from flowers" , "Essential oil from flower" , "Fragrant floral oil" .)
