The most common and most likely answer to this crossword clue is the 4 plus 2 plus 8 letter word PIGS IN BLANKETS
P
I
G
S
I
N
B
L
A
N
K
E
T
S
More clues leading to the result PIGS IN BLANKETS
Buddy explains!
The straight part
We know that "festive treat" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case festive treat = pigs in blankets.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.