1. In a medium bowl, whisk the all-purpose flour, whole wheat flour, salt, pepper, smoked paprika, and cayenne to combine. Add the butter and toss well, separating the cubes and ensuring they are evenly coated in flour. Cut the butter into the flour using your hands or a pastry cutter until it’s about the size of walnut halves. Stir in the Parmesan and cheddar cheese

2. Make a well in the center of the flour mixture and add the milk and water. Toss the mixture with your hands to start to distribute the moisture, then gently knead the dough until it comes together.

3. Turn the dough out, form it into a square about 1 inch/2.5 cm thick, and wrap tightly in plastic wrap. Refrigerate for at least 1 hour (and up to 24 hours).

4. On a lightly floured surface, roll out the dough into a square about 1/2 inch/1 cm thick. Don’t worry about the exact dimensions of the dough, just try to keep it roughly square shaped and focus on the thickness. Fold the dough into quarters. If it feels warm or sticky at all, wrap it tightly and chill for 30 minutes.

5. Repeat step 4, rolling out the dough and performing another fold. Wrap the dough tightly and chill for at least 1 hour (and up to 24 hours)

6. Preheat the oven to 400°F/205°C with the racks in the upper and lower thirds. Line two baking sheets with parchment paper.

7. On a lightly floured surface, roll out the dough into a rectangle about 1/4 inch/6 cm thick; don’t worry about the exact dimensions of the dough, just try to keep it roughly rectangular in shape and focus more on the thick-ness. Use a pastry wheel to cut the dough lengthwise into 1-inch-/ 2.5 cm wide strips, then cut the strips crosswise into 1-inch/2.5 cm squares. (Pieces that aren’t quite squares can still be baked, or you can press the dough back together and re-roll into a rectangle one or two more times.)

8. Transfer the squares to the prepared baking sheets. They won’t spread, so they can be quite close together—within 1/4 inch / 6 mm of each other. Dock the center of each square with the tines of a fork.

9. Bake until the crackers are deeply, evenly golden brown, 15 to 18 minutes. Cool completely on the baking sheets.

Variations

1. CHEESE STRAWS Makes 24 - Prepare the dough as directed. To shape the straws, on a lightly floured surface, roll out the dough to a 16 x 12-inch/41 x 30 cm rectangle.

2. Cut the dough crosswise in half, to form two 8 x 12-inch/20 x 30 cm rectangles. Brush one of the squares all over with egg wash, then place the other piece of dough on top and press down gently all over to adhere. With one of the longer sides of the dough facing you, cut it into 1/2-inch-/ 1 cm wide strips (you should get 24).

3. Transfer the strips to two parchment-lined baking sheets. Use a pastry wheel or sharp paring knife to cut each strip almost in half lengthwise, leaving the top 1/4 inch / 6 mm as a solid piece. Use your thumb to press that portion of the dough firmly against the baking sheet, then twist the two skinny pieces of the dough together. Pinch them together at the other end and use your thumb to press that end firmly against the baking sheet. Refrigerate for 30 minutes to 1 hour.

4. Bake the straws at 375°F/190°C for 22 to 25 minutes, until golden brown. Cool completely on the baking sheet (these are also delicious served warm, but they are a bit more flaky-fragile). Make Ahead and Storage: The crackers (or straws) are best within the first 48 hours, but they will keep for up to 4 days in an airtight container at room temperature. If they become soggy, they can be refreshed on a parchment-lined baking sheet, tented with foil, at 350°F/190°C for 4 to 6 minutes.