Twice-baked bread (4)
I believe the answer is:
rusk
'twice-baked bread' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for rusk that I've seen before include "Bread baked for babies" , "Baby's dry biscuit" , "Small hard biscuit (for babies)" , "Baby's teething biscuit" , "Capital of Malta" .)