Follower has left some cake (4)
I believe the answer is:
flan
'cake' is the definition.
(flan is a type of cake)
'follower has left some' is the wordplay.
'follower' becomes 'fan' (fan is a kind of follower).
'has' means one lot of letters goes inside another.
'some' suggests taking the first letters.
The initial letter of 'left' is 'l'.
'fan' going around 'l' is 'FLAN'.
(Other definitions for flan that I've seen before include "Open pastry case with savoury filling" , "Baked and filled pastry case dish" , "Quiche" , "Open-topped pastry dish" , "pudding!" .)