Place a 5" Lodge cast iron pan inside your air fryer. Preheat the air fryer at 400F for 10 minutes.
Using a blender or a hand mixer, mix eggs and milk together. Add flour, corn starch, vanilla extract and salt, and continue mixing until all ingredients are mixed well.
Open the air fryer and, being very careful – the pan will be very hot, place a tablespoon of butter in the preheated pan. Move the butter with a fork or a knife to get even coverage.
Carefully pour about a quarter of the batter into the hot pan, making sure not to splatter batter on the sides of the pan. Close the air fryer and cook at 400F for 7 minutes. Start checking for doneness after 6 minutes as different air fryers cook differently. The Dutch baby pancake will puff up around the edges and sometimes around the center. Do not open the air fryer too early as it may cause the dough to collapse and your Dutch baby will look more like a traditional flat pancake.
Once your Dutch baby is done baking, remove the pan from the air fryer being very careful as the pan will be very hot, and set it on a cooling rack. Alternatively, take the Dutch baby out with a fork or tongs, and leave the pan inside if you want to make more Dutch babies.
Place the Dutch baby onto a serving plate. You can also serve it on the mini cast iron pan placed on a trivet. Top with condiments (berries, fruit, powdered sugar, maple syrup, etc.) and serve hot.