I there a way to print the regex that is used?

That's what the second line of output above is. Simplification of that regex is left as an exercise to the reader :-) (Update: Nevermind.)

BTW, you can also use the -keep feature to get only the part between the quotes:

use Regexp::Common qw/delimited/;
q{ x "foo \"bar\"" y } =~ /$RE{delimited}{-delim=>'"'}{-keep}/;
print $3, "\n";  # prints: foo \"bar\"
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