Endless capacitor provides ingredients for a pudding (7)
I believe the answer is:
tapioca
'pudding' is the definition.
(tapioca pudding is a kind of pudding)
'endless capacitor provides' is the wordplay.
'endless' says to take the centre.
'provides' indicates anagramming the letters.
The middle of 'capacitor' is 'apacito'.
'apacito' with letters rearranged gives 'TAPIOCA'.
'ingredients for a' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for tapioca that I've seen before include "Starchy foodstuff" , "Hard white cassava grains used for puddings" , "Starchy food" , "pud" , "it thickens" .)