Preheat oven to 450°F. Line two baking sheets with silicone mats or parchment paper cut to fit.

Place both flours, sugar, salt, and pepper in the bowl of a food processor and process until combined.

Add butter and process just until it breaks into small crumbles, about 10 seconds. Add the Parmesan cheese.

With the food processor running, pour in the milk through the spout and process until the dough comes together.

Remove dough from the processor and knead on a lightly floured surface for 5 minutes. Shape into a ball and divide in half.

Roll one half of the dough directly onto a silicone mat or sheet of parchment, rolling it out until it reaches the edges. Transfer the mat and dough to a baking sheet. Repeat with the remaining dough.

Sprinkle both sheets of dough with sea salt and additional ground pepper, then lightly run the rolling pin over the top to press the toppings in.

Using a sharp knife, score the dough into cracker-size squares. Poke each square a couple of times with fork tines.

Bake until set and edges are light golden brown, 10 to 12 minutes, rotating the baking sheets halfway through.

Let crackers cool on the baking sheets for a few minutes, then transfer to a cooling rack to cool completely. Break apart at the score marks and serve.