To make the filling, snap 120g of Aero into a heatproof bowl and melt in the air fryer for 3 minutes at 170°C, then stir until smooth and mix in the cream cheese. Cover and leave to firm up in the fridge for at least 1 hour.Melt the butter in a heatproof bowl for 4 minutes at 170°C. In a large bowl, whisk together the flour, sugar, cocoa and bicarb, then stir through the chocolate chips, mix in the melted butter, then the eggs, until the mixture is well combined. With wet hands, roll into 16 balls and place on a lined baking sheet, pushing them down slightly to flatten.Line the air-fryer shelf with greaseproof paper. Transfer 4 to 6 cookies into the drawer, making sure there’s a 1cm gap between them. Cook for 10 minutes at 170°C (12 minutes from chilled or 15 minutes from frozen), then, using the paper to help you, transfer the cookies to a wire rack to cool, and repeat.Once the cookies are completely cool, sandwich them with the filling, crumbling up the leftover Aero to sprinkle into each one, before sandwiching.This recipe is for a 1-drawer air fryer.