Cakes in ice-cream container brought aboard ship (6)
I believe the answer is:
scones
'cakes' is the definition.
(type of small cake)
'ice-cream container brought aboard ship' is the wordplay.
'ice-cream container' becomes 'cone' (I've seen this in another clue).
'brought aboard' is an insertion indicator (inserted letters come inside or on board).
'ship' becomes 'SS' (prefix in ship names eg SS Great Britain).
'cone' placed into 'ss' is 'SCONES'.
'in' acts as a link.
(Other definitions for scones that I've seen before include "Small unsweetened or lightly sweetened cakes" , "Small plain cakes" , "Small soft cakes of flour, fat and milk - eaten buttered" , "Cakes for tea" , "Small flattish plain cake" .)