Spray the air fryer basket with olive oil.
Pat the turkey breast dry with a paper towel.
In a small bowl, mix together the butter, just one tablespoon of olive oil, garlic, rosemary, salt, and the pepper.
Gently lift the skin away from the meat. Rub about ¾ of the butter mix evenly under the skin so that it coats the meat.
Rub the remaining butter mixture over the outside of the turkey.
Then drizzle the turkey breast with the remaining tablespoon of olive oil and rub that all over the breast.
Put the turkey breast in the air fryer basket, with the skin side up.
Cook at 375 °F (190 °C) for 30-35 minutes or until it reaches an internal temperature of 160 °F (71 °C).
Take the turkey out of the air fryer and cover with foil.
Let it rest for 10 minutes, or until the temperature has reached 165 °F (74 °C).
Slice and serve!
Refrigerate cooled leftovers in an airtight container for up to 4 days.