Web Api set cookie to HttpContext response

I have tried many different says to add a cookie to a HttpContext.Current.Response with no luck. The browser does not see the cookie that I am adding. Help Please!

Here is my API Controller

 public IHttpActionResult Get(string username, string password)
    {

        HttpContext.Current.Response.AddHeader("Access-Control-Allow-Origin", "*");
        HttpContext.Current.Response.AddHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
        HttpContext.Current.Response.AddHeader("Access-Control-Allow-Methods", "*");


         //This does not work
        HttpCookie cookie = new HttpCookie("ACA-Cookie", "This better work!");
        cookie.Expires = DateTime.Now.AddDays(2);
        cookie.Domain = Request.RequestUri.Host;
        cookie.Path = "/";
        HttpContext.Current.Response.SetCookie(cookie);

        //This does not work  
        var cookie = new HttpCookie("MyCookie", DateTime.Now.ToLongTimeString());
        HttpContext.Current.Response.Cookies.Add(cookie);








        return Ok(HttpStatusCode.OK);
    }