The most common and most likely answer to this crossword clue is the 5 plus 2 plus 8 letter word QUEEN OF PUDDINGS
I've seen this crossword clue in Financial Times
Q
U
E
E
N
O
F
P
U
D
D
I
N
G
S
Buddy explains!
The straight part
We know that "Missing element of DESSTS or AFTS" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case missing element of dessts or afts = queen of puddings.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.