1. Pre heat your Air Chef Air Frying Oven to 170°C for 5 minutes.
  2. Sift your flour, brown sugar and caster sugar together.
  3. Using your KAMBROOK bench mixer with the beater attachment, beat the sifted flour mix, milk and eggs until no lumps remain.
  4. Switch your bench mixer onto a low speed, and slowly add the melted butter to the mixture. Beat for 1 minute.
  5. Refrigerate the mixture for 1 hour.
  6. Combine the walnuts and sweet potato into the mixture, and then swirl in the maple syrup.
  7. Spray your muffin cases and fill ¾ of the way up with the mixture.
  8. Cook in the Air Chef for 30 minutes or until a skewer comes out clean when inserted in the middle.