using System;

using System.Xml.Linq;  

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public class Inner {

        public string Name {get;set;}

    }

    public class Outer {

        public List<Inner> Inners {get;set;}    

    }

    public static void Main()

    {

        var outer = new Outer() { Inners = new List<Inner>() { new Inner() {Name ="Cheese"}, new Inner() {Name = "poof"}  }};

        var asd = new XDocument(new XElement("RootElement", outer.Inners.Select(s => new XElement("AnElementName", s.Name) )));

        Console.WriteLine(asd.ToString());

    }

}