Go ballistic making ring-shaped cake across the pond! (5)
I believe the answer is:
donut
'ring-shaped cake across the pond' is the definition.
(I know this)
'go ballistic' is the wordplay.
'go' becomes 'do' (doing is a kind of going).
'ballistic' becomes 'nut' (I can't justify this - if you can you should believe this answer much more).
'do'+'nut'='DONUT'
'making' acts as a link.
Can you help me to learn more?
(Other definitions for donut that I've seen before include "something to eat" , "cake in the American way" , "Sugary deep-fried cake" , "ring coming across the Atlantic" , "cake, American-style" .)