Combine all the ingredients in a food processor except for the water. Blitz until the butter and cheese are the size of large sand granules. With the food processor running, slowly add the water until a pliable dough forms. Turn it out onto a work surface and gently knead until the dough comes together. If the dough is too crumbly, add a few tablespoons of water until it comes together. The dough will hydrate as it sits.
Pat the dough into a disk shape about ½ inch thick. Thoroughly encase in plastic wrap and refrigerate for at least 1 hour, or overnight.
Lightly dust the work surface with flour. Let the dough sit at room temperature for 15 minutes before starting to roll. If the dough was resting overnight, the butter will be quite hard, and the dough will crack.
Roll the dough to 1/8 inch thick. Using a pastry wheel or knife, cut the dough into 2-inch squares. Using a skewer, create a circle in the middle to resemble a cheeze-it shape. Lightly sprinkle with flaky sea salt.
Preheat the air fryer to 375˚F / 190˚C. Place cheeze-its in the air fryer basket, careful to not overlap. Air fry for 8-12 minutes, turning halfway. If the dough is too thick, extend the time in the air fryer to ensure a better crunch. Repeat the process until all cheeze-its are air fried. Store in an airtight container once cooled.