-
1
Special equipment: your favorite 1 1/2-inch cookie cutters
-
2
Whisk together the egg white, vinegar and 3 tablespoons water in a small bowl; set aside.
-
3
Refrigerate the egg yolk in a small bowl, covered, until ready to use.
-
4
Pulse the flour, cornstarch, salt, baking powder, mustard, paprika and turmeric in a food processor to combine.
-
5
Add the butter, Cheddar and Parmesan, and pulse until the butter is completely broken up.
-
6
Pour in the egg white mixture, and pulse until the dough comes together in a ball.
-
7
(It's OK if it's a little wet.)
-
8
Transfer the dough to a large piece of plastic wrap, and pat it into a 1/2-inch-thick round.
-
9
Wrap it up, and refrigerate to chill and firm up the dough, about 1 hour.
-
10
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.
-
11
Roll the dough out on a large piece of parchment (to keep it from sticking to the counter) to about 1/8 inch thick.
-
12
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.
-
13
Gather and reroll the scraps and cut out more crackers; repeat with any remaining scraps.
-
14
(Dust the dough with flour if you find it too sticky.)
-
15
Whisk 2 teaspoons water into the egg yolk.
-
16
Brush the tops of each cracker with the mixture.
-
17
Sprinkle each with some sesame seeds, poppy seeds and the tiniest pinch of salt.
-
18
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.
-
19
Let cool on the baking sheet for a few minutes, then transfer to a cooling rack to cool completely.
-
20
Bake the remaining cutouts.
-
21
Store the crackers at room temperature in an airtight container for up to 2 days, or freeze them for up to 1 week.
