Is this an accurate depiction of what you are attempting?

perl -E '
use strict;
use warnings;
my @projects;
push @projects, [ [ "the", "data" ], "key"];
push @projects, [ [ "more", "data" ], "another key"];
for (@projects) {
  my @data = @{ $_->[0] };
  my $key  = $_->[1];
  say "DATA: @data";
  say "KEY:  $key";
}
'
[download]

OUTPUT:

DATA: the data
KEY:  key
DATA: more data
KEY:  another key
[download]

I suggest you print (or use Data::Dumper/Data::Printer on @contents before it is returned and on $_ in the for loop to see what all is going on.