type
  TMyClass = class
    function createInstance: TMyClass;
  end;
  TMyClassType = class of TMyClass;

function TMyClass.createInstance: TMyClass;
var
  aType: TMyClassType;
begin
  aType := TMyClassType(ClassType);
  Result := aType.Create;
end;

abstract class Parent<K> {
   K createNewIns() {
      return (K) ((Class)((ParameterizedType)this.getClass().getGenericSuperclass()).getActualTypeArguments()[0]).newInstance();
   }
}

Child extends Parent<LOLWHAT> {
   public LOLWHAT createLOLWHAT() {
    return createNewIns();   
   } 
}

interface MyClass {
 MyClass  createInst();  
}

abstract class Parent<K extends MyClass> {
      final K inst;
      public Parent(K myClass) {
        inst = myClass.createInst();
      }
}