Whisk sweetened condensed milk and water in a bowl until combined. Add eggs and vanilla, and whisk until combined. Strain the mixture into a jug. Evenly pour the custard into four 125ml ramekins and cover each with foil. Place in the large basket of the Philips Airfryer. Using the steam function (100C), steam for 12-13 minutes or until just set but still have a slight wobble in the centre (don’t overcook or the custards will curdle). Cool for 15 minutes.
Meanwhile, to make cinnamon crisps, brush both sides of each tortilla with butter and dust with cinnamon sugar. Cut each tortilla into 8 wedges. Place wedges in the smaller basket of the Philips Airfryer and cook on 180C, shaking halfway through, for 8 minutes or until crisp. Open the basket and stand crisps for 1 minute (this helps them crisp up further).
Sprinkle custards with a little cinnamon sugar and serve with cinnamon crisps.
