I always grate my cheddar fresh off the block instead of using the bagged kind. Bagged shredded cheese is coated in a starch that keeps it from clumping in the bag, but that same coating stops it from melting smoothly into the dough. Fresh cheese gives the dough a much softer, more workable texture right from the start.
In a mixing bowl, I combine the grated cheese with the softened butter and mash them together with a fork until they look fully blended. Then I add the flour and salt and keep mixing until a soft, slightly sticky dough forms. If it feels too dry, I add a teaspoon of cold water at a time.
I shape the dough into a flat disc, wrap it in plastic, and pop it in the fridge for about 30 minutes. This step matters more than it seems, since chilled dough rolls out much cleaner and doesn't stick to the pin or the counter as much.
Once the dough has firmed up, I roll it out on a lightly floured surface until it's about an eighth of an inch thick. Thinner dough gives you a crispier finished cracker, so I try not to rush this part. Then I use a pizza cutter to slice it into small, even squares.
I transfer the squares onto a parchment-lined baking sheet, leaving a little space between each one. Before they go in the oven, I poke a small hole in the center of each square with a toothpick, just like the classic Cheez-It look. They bake at 375°F for about 12 to 15 minutes, until the edges turn golden.
I always let the crackers sit on the tray for a few minutes after baking, since they firm up as they cool. Moving them too early can make them crumble apart. Once they've cooled completely, they turn perfectly crisp and ready to snack on.