Preheat an air fryer to 350 degrees F (175 degrees C).
Rub 1 tablespoon olive oil over each mushroom. Sprinkle 1/2 teaspoon Italian seasoning inside each. Set mushrooms in the air fryer basket, cap sides up. Air fry for 3 minutes.
Flip mushrooms over so that the cap is facedown in the basket. Divide pizza sauce between the 2 mushrooms. Cover with 2 tablespoons shredded mozzarella and 1 tablespoon sliced olives. Air fry for 3 minutes.
Place 4 pepperoni slices on each pizza and cover with remaining mozzarella cheese. It is important to weigh the pepperoni down with cheese or the fan will blow them off the pizza.
Air fry until cheese is melted and pepperoni is browned, about 2 minutes.