Grease a 20cm (base size) round cake pan and line the base with baking paper.
Place flour and sugar in a bowl and whisk until well combined. Make a well in the centre and add milk, butter and vanilla. Whisk until well combined. Add apple and fold until combined. Transfer to the prepared pan and smooth the surface.
Place the pan in an air fryer basket. Cook at 150C for 40 minutes or until a skewer inserted into the centre of the cake comes out clean (see tip). Set aside in the pan for 10 minutes before transferring to a wire rack. Sprinkle with cinnamon sugar. Serve warm or at room temperature with custard alongside. Watch our step-by-step video below to see how to make our air fryer apple cake.
