In a saucepan, combine 100ml water with the milk, butter, sugar and salt. Put on a medium heat until the butter melts and the mixture is just about to come to a boil, then take off the heat and quickly stir in the flour until the mix comes together into a dough.
Return the pan to a low heat and cook, stirring constantly, for one to two minutes, until the dough forms a smooth ball and pulls away from the sides of the pan.
Leave to cool slightly, then gradually add the beaten egg, stirring until smooth.
The dough should be thick but pipeable.
Transfer the dough to a piping bag fitted with a large star or round nozzle, then pipe rings on to small squares of greaseproof paper.
Heat the air fryer to 180C, then put some of the chouxnut rings (with their paper bottoms) into the air fryer basket, ensuring they’re not crowded.
Air fry for 10-12 minutes, until puffed and golden – if they’re a bit pale underneath, flip them over and air fry for two to three minutes more.
Leave the chouxnuts to cool slightly, and in the meantime mix the icing sugar and cinnamon with enough water to form a thick glaze – you’ll need about four or five tablespoons in total.
Use a small whisk to combine with the softened butter.
Once the chouxnuts are cool enough to handle, dip them in the glaze to coat the top, then leave the glaze to set before serving.
