Spread 1 to 2 tablespoons of the hazelnut spread on half of the bread slices.
Place the remaining bread slices on top to make sandwiches. Press gently to seal the edges.
Trim the crusts from the sandwiches and cut each one into 3 to 4 strips, creating French toast sticks.
In a shallow bowl, whisk together the eggs, milk, salt, vanilla extract, and ground cinnamon until well combined.
In another shallow bowl, mix the granulated sugar and ground cinnamon to create the cinnamon sugar coating.
Dip each stuffed French toast stick into the egg mixture, making sure they’re coated on all sides.
Air fry at 350 degrees F. for 6-8 minutes or until the French toast is golden brown and crispy, turning the sticks halfway through the cooking.
Roll the sticks in the cinnamon sugar for an extra sweet touch.