Call EditorGUILayout.PropertyField of an element of an array

Hi,

I have a class A that inherits from Monobehaviour, with public variables:

 public class A : MonoBehaviour
 {
   public int num;
   public string s;
 }

When you add A component to a gameobject, you can easily modify the variables, since it has its inspector drawn automatically.

But I have another class B

 public class B : MonoBehaviour
 {
 
 public List<A> vars;
 }

Now I want to create a custom editor for B:

 [CustomEditor(typeof(B))]
 public BEditor: Editor
 {
   public override void OnInspectorGUI()
     {
         var t = target as B;
             
         for (int i = 0; i < t.vars.Count; i++)
         {
             // Here I want to DrawDefaultInspector for t.vars[i] 
             // or in other words the default inspector for an object 
             // of class A
         }
         DrawDefaultInspector();
     }
 }

How do I draw the default inspector of an object inherited from class A, within custom editor of class B?

How can I do this with minimum pain? (Note: I can go reflection, I consider that to be no pain)