Deep Copy ScriptableObject

I've been trying to clone a ScriptableObject with the following script:

 public static class ObjectCopier
 {
     /// <summary>
     /// Perform a deep Copy of the object.
     /// </summary>
     /// <typeparam name="T">The type of object being copied.</typeparam>
     /// <param name="source">The object instance to copy.</param>
     /// <returns>The copied object.</returns>
     public static T Clone<T>(T source)
     {
         if (!typeof(T).IsSerializable)
         {
             throw new ArgumentException("The type must be serializable.", "source");
         }
 
         // Don't serialize a null object, simply return the default for that object
         if (object.ReferenceEquals(source, null))
         {
             return default(T);
         }
 
         IFormatter formatter = new BinaryFormatter();
         Stream stream = new MemoryStream();
         using (stream)
         {
             formatter.Serialize(stream, source);
             stream.Seek(0, SeekOrigin.Begin);
             return (T)formatter.Deserialize(stream);
         }
     }
 }  

But it is producing this error:

SerializationException: Type UnityEngine.ScriptableObject in assembly UnityEngine, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null is not marked as serializable.

How can we perform a deep copy in this case?