语法PHP cURL HTTP包含变量的标头

Below is a sample of my code. I need to send a field in the header named "Cookie" and it's value should be what i have in the $cookie variable.

Any chance someone could tell me the correct syntax in the array to include the variable in there?

$headers = array(
    "Cookie:" .$cookie  
);


curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

For example,

First time i "hit" the server i get back

Cookie:JSESSIONID=280FC268DDBA4260AB7F9A5C67304C5C

If i then send it back to the server like this

$headers = array(
        "Cookie:JSESSIONID=280FC268DDBA4260AB7F9A5C67304C5C",   
);

It won't respond with a new cookie. But it won't seem to work when i pass it as an variable.