Crossword Genius

Mess up the topping for summer puddings (5)

Ross

I believe the answer is:

duffs

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

'puddings' is the definition.
(duff is a kind of pudding)

I cannot understand how the rest of the clue works.

Can you help me to learn more?

I've seen this clue in The Independent.
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.