The most common and most likely answer to this crossword clue is the 6 plus 3 letter word EASTER EGG
I've seen this crossword clue in The Times
E
A
S
T
E
R
E
G
G
More clues leading to the result EASTER EGG
- Segregate nutty chocolate product
- Segregate criminal that’s hunted in spring?
- European daisy, say, good seasonal item
- Flower, say, brought in for one seasonal gift
- Is it sweet to celebrate a fast finish?
- Segregate unusual DVD feature?
- Timely gift set unwrapped since cart’s back before horse
- Hunt’s target next spring?
- Point-to-point on horse for young hunter’s quarry?
- Candy gadgeteers nod off
Buddy explains!
The straight part
We know that "Is it sweet to celebrate a fast finish" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case is it sweet to celebrate a fast finish = easter egg.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.