Expert’s baking attempt (7)
I believe the answer is:
hotshot
'expert's' is the definition.
(hotshot is a kind of expert)
'baking attempt' is the wordplay.
'baking' becomes 'hot' (similar in meaning).
'attempt' becomes 'shot' (shot is a kind of attempt).
'hot'+'shot'='HOTSHOT'
(Other definitions for hotshot that I've seen before include "Top player" , "Expert" , "Important person" , "Showily successful person" , "successful type?" .)