Recipe Instructions:
2 cups all-purpose flour
3/4 teaspoon kosher salt, plus more
1/2 teaspoon baking powder
7 1/2 ounces finely grated sharp cheddar (about 3½ cups)
6 tablespoons unsalted butter, room temperature
2 tablespoons (or more) ice water
1 large egg white, lightly beaten
In a food processor, pulse the flour, salt, and baking powder until combined. Add the cheese and butter and pulse until very well combined. Add the water and pulse until the dough is just wet enough to hold together when squeezed. Add up to 2 tablespoons more water if necessary.
Divide the dough between two pieces of plastic wrap. Press each half of dough into a flat square, wrap well, and chill for at least 30 minutes.
Working with one square at a time, roll the dough out to a scant ⅛ inch thick. Using a fluted pastry wheel, cut the dough into ¾-inch-wide strips. Cut the dough in the other direction to make ¾-inch squares. Using the flat end of a wooden skewer, poke a hole in the center of each square. Freeze the dough for 10 to 15 minutes, until firm. Repeat with the remaining dough.
Heat the oven to 350°F. Brush half of the dough (keep the remaining dough in the freezer) with the egg white and sprinkle with salt. Using an offset spatula, gently break the dough apart and place the squares on a parchment-lined baking sheet. Bake for 14 to 16 minutes, until puffed, set, and browned on the bottom. (Make sure to cook them well so that the finished crackers are crisp. Completely frozen dough may take a few extra minutes to bake.) Transfer the parchment with the baked crackers to a wire rack. Repeat with the remaining frozen crackers. Store the cooled crackers in an airtight container.