The most common and most likely answer to this crossword clue is the 6 letter word PARKIN
I've seen this crossword clue in The Guardian
P
A
R
K
I
N
Buddy explains!

The straight part
We know that "gingerbread" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case gingerbread = parkin.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.
What does PARKIN mean?
PARKIN noun- A traditional soft cake of Northern England, usually made with oatmeal and treacle.
- A particular protein, mutations in which are associated with Parkinson's disease.