You don't need to restructure your hashes, you just need to pass separately to Dumper each thing you want listed separately.

my %self;
my %abldcache = (test1 => [], test2 => [qw(one two three)]);

$self{abldcache} = \%abldcache;

use Data::Dumper;

sub per_key {
    my ($name, $href) = @_;
    my @hkeys = keys %$href;
   ([@$href{@hkeys}], [map {"$name\{$_}"} @hkeys])
}

print Data::Dumper->Dump(per_key('$self{abldcache}', $self{abldcache} 
+)), "\n";
__END__
# Yields:
$self{abldcache}{test1} = [];
$self{abldcache}{test2} = [
                            'one',
                            'two',
                            'three'
                          ];
[download]

Close enough?