It's of consuming interest if you're thinking of an apple (7)
I believe the answer is:
strudel
'apple' is the definition.
The answer and definition can be both things that one consumes for nourishment as well as being singular nouns.
Maybe there's an association between them I don't understand?
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for strudel that I've seen before include "German pie" , "Baked dish" , "Germany pastry" , "Fruit-filled pastry from Austria" , "German dessert" .)