Capture entertaining ace sporting bun (7)
I believe the answer is:
teacake
'bun' is the definition.
(type of bun)
'capture entertaining ace sporting' is the wordplay.
'capture' becomes 'take' (I've seen this before).
'entertaining' means one lot of letters goes inside another (inviting in, as for dinner).
'sporting' indicates an anagram.
'ace' anagrammed gives 'eac'.
'take' placed around 'eac' is 'TEACAKE'.
(Other definitions for teacake that I've seen before include "Afternoon food?" , "food item" , "Scones with raisins, toasted and buttered" , "Something to eat in the afternoon?" , "Sweet bun" .)