Preheat the air fryer: Set to 360°F (182°C) for 3–5 minutes so it’s hot when the bread goes in.
Cut the bread: Slice the baguette into 1-inch cubes. Aim for uniform pieces so they cook evenly.
Make the garlic butter: In a bowl, mix melted butter, olive oil, minced garlic, parsley, a pinch of salt, and a few grinds of black pepper. Taste and adjust salt.
Toss the bread: Add bread cubes to a large bowl. Drizzle the garlic butter over the top and toss gently until every piece is lightly coated. Sprinkle half the Parmesan and toss again.
Arrange in the basket: Place the bread in a single layer in the air fryer basket. A little overlap is fine, but avoid packing it in. Work in batches if needed.
Air fry: Cook for 5 minutes. Shake the basket or stir, then cook another 2–4 minutes until the bites are golden and crisp on the edges. Keep an eye on them to avoid burning.
Finish and serve: While still hot, toss with the remaining Parmesan. Add a little extra parsley or red pepper flakes if you like. Serve right away.