Aim to bake dog treat after leaving party (6)
I believe the answer is:
target
'aim' is the definition.
(both can mean a goal or purpose)
'bake dog treat after leaving party' is the wordplay.
'bake' indicates an anagram (I've seen 'baked' mean this).
'after leaving' suggests deleting specific letters.
'party' becomes 'do' (do can informally mean a party).
'dog'+'treat'='dogtreat'
'dogtreat' with 'do' taken out is 'gtreat'.
'gtreat' is an anagram of 'TARGET'.
'to' is the link.
(Other definitions for target that I've seen before include "Object to be aimed at" , "Goal, objective" , "Reference point to shoot at" , "Objective, mark" , "Butt" .)