Spooner's work with butter brand reveals a craft of sorts (3,6)
I believe the answer is:
oil tanker
'craft of sorts' is the definition.
'oil tanker' can be an answer for 'craft' (oil tanker is a kind of craft). I'm not certain of the 'of sorts' bit.
'spooner's work with butter brand reveals a' is the wordplay.
I cannot quite see how this works, but
'a' could be 'an' and 'an' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for oil tanker that I've seen before include "Ship carrying "black gold"" , "[See] ocean-going vessel" , "On which crude" , "Ship carrying fuel" , "Fuel transport ship" .)