use warnings;
use strict;
use Data::Dumper;

my %HoH = (
  first => {1 => 'First 1', 2 => 'First 2'},
  second => {1 => 'second ', 2 => 'second 2'});

print "Original hash: " . Dumper (\%HoH);

my %newHoH = %{inAndOut (%HoH)};

print "\nnew hash: " . Dumper (\%newHoH);


sub inAndOut {
  my (%hash) = @_;
  
  print "\nin sub: " . Dumper (\%hash);
  return {%hash};
}