The most common and most likely answer to this crossword clue is the 5 plus 10 letter word MARIE ANTOINETTE
I've seen this crossword clue in Financial Times
M
A
R
I
E
A
N
T
O
I
N
E
T
T
E
More clues leading to the result MARIE ANTOINETTE
- One supposedly recommending cake in slices transformed into meat-eater
- Austrian woman based near Paris who had a fantastic brioche recipe?
- Queen Mum right: that’s a new weighty piece, covering one better missed outside
- Queen, making nation irate, met guillotine, finally
- Queen who made herself unpopular, namely in dreadful rant at one time
- Train at one time troubling English queen
- Termination at extremes of extravagance ordained for her?
- Unsympathetic French queen associated with a ‘pain free’ situation!
Buddy explains!
The straight part
We know that "Austrian woman based near Paris who had a fantastic brioche recipe?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case austrian woman based near paris who had a fantastic brioche recipe? = marie antoinette.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.