Preheat air fryer at 160°C for 3 minutes.
Make four even slices on each tomato, three-quarters of the way down.
Stuff one basil leaf and a piece of mozzarella into each slice.
Season with salt and pepper.
Place stuffed tomatoes in ungreased air fryer basket.
Cook for 3 minutes.
Transfer to a large serving plate.
Drizzle tomatoes with olive oil and balsamic vinegar and serve.