Mix the dry ingredients in a medium bowl or large jug.
Shred the zucchini and place in a large mixing bowl.
Add the other wet ingredients and mix for 2-3 minutes until well combined.
Add the dry ingredients and mix on a low speed until just combined [Note 1].
Preheat the air fryer to 400°F/ 200°C.
Scoop the muffin batter into muffin cases [Note 2]. Work in batches according to how many will fit in your air fryer in one go.
Carefully place muffins into the air fryer basket [Note 3].
Air fry muffins at 400°F/ 200°C for 4 minutes.
When the cook time is up do not open the air fryer. Reduce the temperature to 320°F/ 160°C and air fry for an additional 14-16 minutes until a cake tester or toothpick comes out clean.
Remove the muffins from the air fryer and allow to cool on a cooling rack.
Notes
Don't over-mix as this will give you overly dense chewy muffins. Some streaks of flour remaining is OK.
If you want tall muffins with big tops like in my photo, then fill the muffin cases to the top (makes 8). For regular sized muffins, fill the muffin cases 3⁄4 full (makes 10).
Paper muffin cases will spread during cooking, however you can reduce that by placing them inside silicon muffin cases, or just cooking your muffins direct in the silicone muffin cases (give them a quick spray with cooking oil before adding the batter).