Depending on the source of the mustache it may resolve the double quotes as html codeded, eg. &
To escape that you can use the three curly brackets
Calling with:
{{ test }}
would give you:
Q & A
..but calling with:
{{{ test }}} or {{ &test }}
Sometime the quote gets escaped with backslash \" casuing the call to fail, then if possible replace the double quote " with single quote '
This you can do by using a simple groovy script.