Who's Keith to keep a jam jar for biscuit? (8)

I believe the answer is:

macaroon

I'm a little stuck... Click here to teach me more about this clue!

'for biscuit?' is the definition.
(macaroon is a kind of biscuit)

I can't explain the remainder of the clue.

(Other definitions for macaroon that I've seen before include "cake" , "Biscuit of egg-white and almonds or coconut" , "Type of biscuit" , "Sweet bit of food" , "Sweet almond biscuit" .)

I've seen this clue in The Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.