my %aMenu = { label => "  A", MenuItems => [ @MenuItems ] };

##</code><code>##

my %aMenu = ( label => "&nbsp; A", MenuItems => [ @MenuItems ] );

##</code><code>##

# if  @MenuItems actually has something it it, then   MenuItems => [@MenuItems]   is fine
# but for simplicity i just made it MenuItems => []
my %menus = ( a => { label => "&nbsp; A", MenuItems => [] },
              b => { label => "&nbsp; B", MenuItems => [] },
              c => { label => "&nbsp; C", MenuItems => [] },
);
#OR:  my %menus = map { lc($_) => {label => "&nbsp; $_", MenuItems => []} } 'A' .. 'C';

# then:
foreach my $app (map {lc $_} @sorted_applications) {
  push @{ $menus{$app}->{MenuItems} }, $app;
}

##</code><code>##

my %menus;
foreach my $app (map {lc $_} @sorted_applications) {
  $menus{$app} ||= { label => "&nbsp; ".uc($app), MenuItems => [] };
  push @{ $menus{$app}->{MenuItems} }, $app;
}