Preheat oven to 375 degrees. Alternately, preheat air fryer to 380 degrees.

Cut about 1/3 of the garlic head off of the top, so that the cloves are exposed. Place each head of garlic on a sheet of aluminum foil.

Drizzle with olive oil and sprinkle with salt and pepper. Wrap the foil to enclose the garlic head and place on a baking sheet.

Cook for about 30 minutes in the oven, or 16-20 minutes in the air fryer, or until the cloves are very soft. Remove from oven or air fryer and cool completely.

Squeeze the desired number of garlic cloves into a food processor. Add the butter and pulse several times, until smooth.

Store in an covered container in the refrigerator. Bring to room temperature before serving.