Slice the bread into 1-inch thick pieces cut on a bias (slicing the bread into longer angled slices leaves more room for more garlic butter on each slice). Set aside.
In a mixing bowl, combine the softened butter, minced garlic, chopped parsley, olive oil, salt, and black pepper. Mix until all ingredients are combined.
Spread a generous amount of the garlic butter mixture onto one side of each bread slice. If you're using Parmesan cheese, sprinkle it on top of the buttered slices.
Preheat the air fryer to 370F for about 3 minutes.
Place the buttered slices of bread in the basket in a single layer, butter side up. Make sure they are not overlapping so that they can cook evenly (you’ll likely have to cook this in batches).
Air fry the bread for about 3-4 minutes, or until golden brown and crispy. Keep an eye on the bread towards the end to make sure it doesn’t burn.
Remove the garlic bread from the air fryer and serve.