Dissolute rake, donning layer, is to pay heed (7)
I believe the answer is:
hearken
'is to pay heed' is the definition.
(I've seen this in another clue)
'dissolute rake donning layer' is the wordplay.
'dissolute' indicates anagramming the letters.
'donning' means one lot of letters goes inside another (I've seen this in other clues).
'layer' becomes 'hen' (something which lays - eggs in this case).
'rake' with letters rearranged gives 'arke'.
'arke' placed into 'hen' is 'HEARKEN'.
(Other definitions for hearken that I've seen before include "Listen in old way" , "Old attend" .)