Process the cheese, flour, cornstarch and salt in a food processor until combined. Add the butter and process for about 20 seconds or until mixture resembles wet sand. Add the ice water and pulse until the dough comes together, about 10 pulses.
Transfer dough to floured surface and divide in half. Form into two 6 inch circles. Wrap in plastic and refrigerate for 1 hour.
Preheat oven to 350°F and line two large baking sheets with parchment paper.
Place dough on floured surface and roll out to a 9 inch square where the dough is about 1/8 inch thick. Use a pizza cutter to cut 8 strips 1 inch wide. Cut 8 more perpendicular strips so you have 64 crackers. Use a wooden skewer to poke a hole into each square.
Transfer squares to baking sheet and sprinkle with sea salt. Bake for 25 minutes or until golden brown on the edges, rotating the sheet halfway through. Let cool completely before serving.
Don’t use pre-shredded cheese. It doesn’t taste as good and also has additional ingredients that you don’t need.
You want cold butter to help create the crunchy/buttery texture.
Use parchment paper so the pepper jack cheese crackers don't stick.
The longer you bake, the crunchier they become. If you want a slightly softer cracker, bake for about 20 minutes. I found 25 minutes to be the right time.
Store leftover crackers at room temperature. If they are sealed tightly, they’ll lose their crunch.