Better yet, use the multiple argument form to avoid (lack of) escaping problems and to simplify the code.

my @cmd = (
  'ls',
  '-l',
  'file1',
  'file2',
  'file with space',
);

my $results = do {
   open(my $fh, '-|', @cmd) or die("Unable to run $cmd[0]: $!\n");
   local $/;
   <$fh>
};
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PS - Why did you use and there instead of making two statements?!

Update: Fixed wrong variable name.