Clue: Plump for pudding (4-4)
Answer: ROLY-POLY
Explanation: Plump for pudding (4-4)
Double definition. 
A roly-poly is a pudding made of a sheet of suet pastry covered with jam or fruit, formed into a roll, and steamed or baked. It used to be a staple of school dinners, but seems to have fallen out of fashion.