Slice the top quarter off each head of garlic to expose the cloves inside. Remove any loose, papery outer skin, but keep the heads intact.
Place each garlic head cut-side up on a small square of aluminum foil. Drizzle 1 teaspoon of extra virgin olive oil over the exposed cloves of each head, letting it seep down between them. Season lightly with salt and black pepper.
Wrap each garlic head snugly in its foil, creating a sealed packet with the seam on top.
Place the foil-wrapped garlic packets in the air fryer basket. Air fry at 370 degrees F for 25 to 30 minutes, until the cloves are deeply golden and completely soft when you press the side of the packet gently.
Carefully unwrap the foil and let the garlic cool for about 5 minutes. Squeeze the roasted cloves out of the skins by pressing from the bottom of each head. The garlic should slide out easily in a buttery, caramelized paste.
Use the roasted garlic immediately as a spread on crusty bread, stirred into mashed potatoes, or mixed into sauces and dressings. Store any leftovers in a small jar covered with olive oil in the refrigerator for up to one week.