Small pastry later crumbles in transit after dropping load (7)
I believe the answer is:
tartlet
'small pastry' is the definition.
(I've seen this in another clue)
'later crumbles in transit after dropping load' is the wordplay.
'crumbles' is an anagram indicator.
'in' means one lot of letters goes inside another.
'after dropping load' means to remove the middle letters (the word is unloaded of its middle letters).
'transit' with its centre removed is 'tt'.
'later' is an anagram of 'artle'.
'artle' inserted inside 'tt' is 'TARTLET'.
(Other definitions for tartlet that I've seen before include "little cake" , "Small quiche" , "single pastry" , "pastry dish" , "Small filled pastry case" .)