Cake made by special computers with flour student's left (5,4)
I believe the answer is:
petit four
'cake' is the definition.
(petit four is a kind of cake)
'special computers with flour student's left' is the wordplay.
'special' becomes 'pet' (I've seen this in another clue).
'computers' becomes 'IT' (information technology).
'with' means one lot of letters go next to another.
'student' becomes 'L' (as in L-plates for learner drivers).
'left' is a deletion indicator (some letters have left).
'flour' with 'l' taken out is 'four'.
'pet'+'it'+'four'='PETIT FOUR'
'made by' is the link.
(Other definitions for petit four that I've seen before include "Delicacy" , "Item of confectionery" , "cake or biscuit" , "Small cake, often decorated with marzipan" , "Small fancy cake" .)