Mix together the 4 eggs, 150ml milk, teaspoon vanilla extract and 1 teaspoon of ground cinnamon.
Pour the French toast egg mixture in to a shallow bowl.
Slice the bread into sticks. I tend to make 3-4 pieces from each slice of bread. If you're using crusts, perhaps from making sandwiches, then I would recommend freezing these in a ziplock bag until you have a few weeks worth.
Add the sticks of bread to the dish and then turn them over to ensure that they coated well and have time to soak up the French toast mixture.
Place the sticks into your air fryer basket, shaking off any excess first, in a single layer.
Air fry at 180C (355F approx) for 2-3 minutes.
Turn the French toast sticks over using tongs, or just by shaking the air fryer basket gently. This helps to avoid sticking and ensures even cooking time.
Air fry for another 2-3 minutes at 180C (355F) approx.
If you are a fan of extra crispy french toast sticks then you will want to turn the maximum heat of your air fryer up, this is usually 200C (390F approx) or 220C (430F approx) for 1 minute. If you're using a Ninja Dual model you'll likely have a mode called air crisp, which goes to 240C (465F approx) and I only use that for 30 seconds.
You can place parchment paper in the bottom of your air fryer basket, if you want to cut down on the mess, however, make sure that this is low down in the air fryer basket and cannot raise up and get onto the element as it WILL catch fire!
I've also used a little cooking spray in the bottom of the basket sometimes, to prevent sticking, but this step isn't really necessary.