Plump for pudding (4-4)
I believe the answer is:
roly-poly
I believe this clue is a double definition.
'plump' is the first definition.
(I've seen this before)
'pudding' is the second definition.
(I know that roly-poly is a type of pudding)
'for' is the link.
(Other definitions for roly-poly that I've seen before include "Plump and round" , "Plump in appearance- steamed pudding" , "Substantial" , "Short and plump" , "Desert pudding of suet and jam" .)