There's nothing wrong with singletons. This would be a good time to explore Moose, especially MooseX::Singleton. Following up on Anonymous Monk's "new", here's what I tried:

package Foo;
use MooseX::Singleton;

has stuff => (
    is      => 'rw',
    isa     => 'HashRef[Str]',
    default => sub { { default => 'new' } },
);

package main;

my $instance = Foo->instance;
my $same     = Foo->instance;

use Data::Dumper::Concise;
print Dumper($same);
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