Preheat the oven to 175c and grease a 9x13 baking pan. Set aside.
Peel, core and chop the apples. Set aside.
Attach the whisk attachment to your stand up electric mixer (or handheld electric mixer). Beat the eggs and sugar on high for about 2 to 3 minutes, until light yellow, thickened and about triple its size.
Lower the speed to low and beat in the vanilla and flour.
Quickly mix the baking soda and vinegar and add it to the batter. Mix batter gently.
Arrange the chopped apples on the baking pan. Then pour batter over the apples.