Preheat your air fryer. Set it to 360–370°F (182–188°C). A short preheat (2–3 minutes) helps the bread crisp evenly.
Prep the bread. Slice your loaf lengthwise for larger pieces or into 1–1.5-inch thick slices if your air fryer basket is smaller. Avoid paper-thin slices; they dry out quickly.
Make the garlic butter. In a bowl, combine softened butter, olive oil, minced garlic, parsley, a pinch of salt, and pepper.
If you like bolder flavor, add a little garlic powder or onion powder.
Spread generously. Coat the cut sides of the bread with the garlic butter mixture, edge to edge. Don’t skimp—this is what keeps the crumb tender.
Add the cheese. Top with mozzarella, then sprinkle Parmesan over it. Press the cheese lightly so it adheres.
Air fry in batches. Place the bread in the basket, cheese side up, without overlapping.
Cook for 5–7 minutes, until the edges are crisp and the cheese is melted and lightly golden.
Check and adjust. If the cheese is browning too fast, lower the temperature by 10–20 degrees. If you want deeper color, add 1–2 more minutes.
Finish and garnish. Remove to a cutting board, rest for 1–2 minutes to set the cheese, then sprinkle with more parsley or a pinch of red pepper flakes.
Slice and serve. Cut into thick strips or squares and serve hot.