Can't find created block
Both of the below formats should work,

function my_header_block_info() {
  return array(
    "headers" = array( //I have Replaced =&gt; with = on your code
      "info" =&gt; "Header Block",
      "cache" =&gt; DRUPAL_NO_CACHE,
    ),
  );
}


-----OR-----

function my_header_block_info() {
    $blocks = array();
    $blocks['headers'] = array(
        'info' =&gt; 'Header Block',
        'cache' =&gt; DRUPAL_NO_CACHE
    );
    return $blocks;
}


Make sure to clear the cache after updated your code.