Prep the peppers: Slice off the tops and remove the seeds and membranes. If they wobble, trim a thin slice off the bottom to help them stand.
Lightly season the insides with a pinch of salt.
Sauté the aromatics: Heat olive oil in a skillet over medium. Add onion and cook until translucent, 3–4 minutes. Stir in garlic and cook 30 seconds until fragrant.
Brown the protein: Add ground meat.
Season with salt, black pepper, Italian seasoning, and smoked paprika. Cook, breaking it up, until browned and no longer pink, 5–7 minutes. Drain excess fat if needed.
Build the filling: Stir in crushed tomatoes (and diced tomatoes if using).
Simmer 2–3 minutes to meld flavors. Fold in cooked rice, mozzarella, and Parmesan. Taste and adjust salt or pepper.
The mixture should be thick and spoonable.
Preheat the air fryer: Set to 360°F (182°C) for 3–5 minutes. Lightly spray the basket with cooking spray.
Stuff the peppers: Spoon filling into each pepper, packing gently. Leave a little space at the top for cheese.
Air fry, first pass: Arrange peppers upright in the basket without crowding.
Cook at 360°F (182°C) for 10 minutes.
Add cheese and finish: Sprinkle more shredded cheese on top. Air fry another 5–8 minutes, until the peppers are tender and the cheese is melted and lightly browned. Thicker peppers may need up to 20 minutes total.
Rest and garnish: Let peppers rest 3–5 minutes to set.
Top with chopped parsley or basil before serving.