In a food processor, combine the sharp yellow cheddar cheese, all-purpose flour, cornstarch, and salt. Pulse until resembling wet sand, about 15-20 seconds. Add cold, cubed butter and pulse until coarse crumbs. Gradually drizzle cold water while pulsing until dough clumps together but isn’t sticky.

Transfer the dough onto a floured surface and divide into two equal portions. Shape each into a square and wrap tightly in plastic wrap. Refrigerate for 45 minutes.

Preheat oven to 350°F (177°C) and line two baking sheets with parchment paper. Roll each square into 9-inch thickness, trim to 8-inch squares, cut into 64 smaller squares, and poke a hole in the center.

Sprinkle a pinch of sea salt over each cracker, then bake for 16-20 minutes until golden brown and crispy.

Allow to cool on baking sheets for optimal crispness, then transfer to a wire rack to cool completely.