Puddings rising under pressure (8)
I believe the answer is:
stressed
'under pressure' is the definition.
(I've seen this in another clue)
'puddings rising' is the wordplay.
'puddings' becomes 'desserts' (I've seen this before).
'rising' shows that the letters should be reversed in order (going up in a down clue).
'desserts' backwards is 'STRESSED'.
(Other definitions for stressed that I've seen before include "Under great strain" , "Emphasized or strained" , "Emphasised, underlined" , "on edge" , "Insisted" .)