To prepare the peppers, slice the tops off and remove any veins or seeds inside. In a medium sized saucepan over medium high heat add the olive oil and onion. Cook until almost tender. Add in the ground beef and cook and crumble until no longer pink.
Add in the diced tomatoes, tomato sauce, rice, Italian seasoning, garlic powder, and salt and pepper.
Stuff the peppers with the mixture and place in the basket of the air fryer.
Cook the peppers at 360 degrees until tender for for 10 minutes. Top with cheese and then cook for an additional 2-3 minutes.