Ingredients

  • 1 large egg, separated
  • 1 tablespoon cider vinegar
  • 1 1/2 cups gluten-free all-purpose flour, plus more for dusting
  • 1 tablespoon cornstarch
  • 3/4 teaspoon kosher salt, plus more for sprinkling
  • 1/2 teaspoon baking powder
  • 1/2 teaspoon dry mustard
  • 1/2 teaspoon paprika
  • 1/4 teaspoon turmeric
  • 6 tablespoons unsalted butter, cut into small pieces
  • 1/2 cup shredded Cheddar
  • 1/2 cup grated Parmesan
  • 1 tablespoon white sesame seeds
  • 2 teaspoons poppy seeds

Method

  • Special equipment: your favorite 1 1/2-inch cookie cutters
  • Whisk together the egg white, vinegar and 3 tablespoons water in a small bowl; set aside.
  • Refrigerate the egg yolk in a small bowl, covered, until ready to use.
  • Pulse the flour, cornstarch, salt, baking powder, mustard, paprika and turmeric in a food processor to combine.
  • Add the butter, Cheddar and Parmesan, and pulse until the butter is completely broken up.
  • Pour in the egg white mixture, and pulse until the dough comes together in a ball.
  • (It's OK if it's a little wet.)
  • Transfer the dough to a large piece of plastic wrap, and pat it into a 1/2-inch-thick round.
  • Wrap it up, and refrigerate to chill and firm up the dough, about 1 hour.
  • Position 2 oven racks at the top and bottom third of the oven, and preheat the oven to 350 degrees F. Line 2 baking sheets with parchment.
  • Roll the dough out on a large piece of parchment (to keep it from sticking to the counter) to about 1/8 inch thick.
  • Cut shapes out with a 1 1/2-inch cookie cutter, and transfer the cutouts to the prepared baking sheets, spacing them about 1/2 inch apart.
  • Gather and reroll the scraps and cut out more crackers; repeat with any remaining scraps.
  • (Dust the dough with flour if you find it too sticky.)
  • Whisk 2 teaspoons water into the egg yolk.
  • Brush the tops of each cracker with the mixture.
  • Sprinkle each with some sesame seeds, poppy seeds and the tiniest pinch of salt.
  • Bake 2 baking sheets of crackers at a time, until the crackers are deep golden brown on the bottom, about 20 minutes, rotating the sheets about halfway through.
  • Let cool on the baking sheet for a few minutes, then transfer to a cooling rack to cool completely.
  • Bake the remaining cutouts.
  • Store the crackers at room temperature in an airtight container for up to 2 days, or freeze them for up to 1 week.