My questions are does this already exist?

Yes! It's called threads::async(). Could it be any easier?

#! perl -slw
use strict;
use threads;
use Data::Dumper;

## "fork" the subroutine
my( $thread ) = async {
    my %hash = (
        A => [ 1 .. 10 ],
        B => { 'a' .. 'z' },
        C => 'Just a big scalar' x 100,
    );
    return \%hash;
};

## Do other stuff
sleep 10; 

## Get the complex results
my( $complexData ) = $thread->join;

## Display them
print Dumper $complexData;

__END__
c:\test>junk8
$VAR1 = {
          'A' => [
                   1,
                   2,
                   3,
                   4,
                   5,
                   6,
                   7,
                   8,
                   9,
                   10
                 ],
          'C' => 'Just a big scalarJust a big scalarJust a ...
alarJust a big scalarJust a big scalarJust a big scalarJus ...
          'B' => {
                   'w' => 'x',
                   'e' => 'f',
                   'a' => 'b',
                   'm' => 'n',
                   's' => 't',
                   'y' => 'z',
                   'u' => 'v',
                   'c' => 'd',
                   'k' => 'l',
                   'q' => 'r',
                   'g' => 'h',
                   'i' => 'j',
                   'o' => 'p'
                 }
        };
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