Cake is miracle baked without topping (6)
I believe the answer is:
eclair
'cake' is the definition.
(eclair is a type of cake)
'miracle baked without topping' is the wordplay.
I cannot really understand how this works, but
'topping' could be 'ai' (resembles A1, term for excellent or topping) and 'ai' is found in the answer.
This explanation may well be incorrect...
'is' acts as a link.
Can you help me to learn more?
(Other definitions for eclair that I've seen before include "Lacier type of confection" , "Chocolate-topped, cream-filled cake" , "Finger-shaped, chocolate-iced, cream-filled cake" , "Food" , "Bakery item" .)