How can I match a string delimited by double asterisk ('**') with Text::Balanced?

$str = '**bold words**'
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My first try:

warn Dumper extract_tagged( 
    $str,
    '**',
    '**',
);
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Now perl complains about nested qualifiers because Text::Balanced creates a regex that starts with /\G**. So I try escaping the '*'s:

warn Dumper extract_tagged( 
    $str,
    '\*\*',
    '\*\*',
);
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That leads to a 'quantifier follows nothing' regexp error. Okay, double escape it, methinks, but that gives the same error, 'quantifier follows nothing' in the regexp Text::Balance creates.

When I try it with three or more '\'s, there are neither errors nor results and I am thoroughly confused because of all the escaping of escaping chars, I played around with quotemeta, but that didn't work either so I turn to you:

Is there a way to match a string delimited by multiple regexp metacharaters like '*' and if so, what would be the least confusing way to implement it?