Take the extra sharp cheddar cheese (8 ounces) and unsalted butter (4 tablespoons) out of the refrigerator (you want them cold) and cut into small cubes (about ½" in size).
In the bowl of a stand-mixer, add just the extra sharp cheddar cheese and beat on medium-high speed (a level 6 on kitchenaid) for about 30 seconds until the cheese has broken down and looks "creamed together". When finished, prep for the next step by scraping down the sides of the beater or bowl. (*If you don't have a stand-mixer, see tip box below.)
Turn the mixer back on medium-high speed and add in the cubes of the unsalted butter and salt (½ teaspoon). Mix for another 30-45 seconds until the cheese and butter are creamed together. Scrape down sides of bowl again. Texture Tip: The texture should be creamy and you shouldn't see any chunks of cheese throughout. If you do, mix for a little longer.
Turn the mixer to low speed then slowly add in the all-purpose flour (1 cup). Once it's all added, turn the mixer up to medium-high speed and beat for 30 seconds until all flour is incorporated. Texture Tip: At this point, the texture will be a dry and crumbly. Have no fear, the ice water is here!
Turn the mixer on low speed and add the ice water, 1 tablespoon at a time. When I make this, my mixture only takes 2 tablespoons of water total. But depending on climate and specific brands of ingredients you use, you may need to add up to 3 tablespoons. Texture Tip: You want the dough to feel solid and soft, but not sticky (a lot like play-doh). You should be able to press your finger in it and not have it stick to your finger.
Once mixed:1. Sprinkle flour on a piece of parchment paper and place dough ball on top.2. Use your hands to "knead" the dough into a solid ball (about 20-30 seconds). Again, this should not be sticky so if it is, add a little flour. The goal here is to have a solid ball.3. Flatten the dough ball into a thick disc. Just like I do with my cut out sugar cookies, this helps prevent cracking as you start rolling.4. Use a rolling pin to roll dough into a 1/16" thickness (aka, really thin where it's just a step above being translucent). I use my trusty rolling pin on the lowest yellow ring. Once rolled, use a sharp knife to cut into 1" squares. You can also use fun 1-2" cookie cutter shapes like I did to create stars, hearts, or animal shapes like goldfish. Tip: For the cleanest cut, use a pizza cutter OR use a large knife to press directly down on the dough. Pressing down (as opposed to sliding the knife) will help prevent the edges from crinkling. After cutting, transfer the cut crackers to a parchment-lined baking tray and bake at 375℉ for 15-17 minutes. If you made smaller or larger shapes than 1" (or made them thinner!), you may need to bake for a little less or longer.Baking Tip: Because all ovens bake differently, start checking on them around the 10-12 minute mark. You want them to have a little brown on the edges, but still have the orange color. To test for doneness, take one off the tray, allow it to slightly cool on the pan for 2-3 minutes, then give it a taste. If it's not crunchy, put back in the oven for 1-3 minutes. Depending on how thick you rolled them, they may need several extra minutes. The main thing here is that if you try them and the texture is soft, you need to put them in to bake longer.