¾ cup flour, plus more for rolling
1 cup finely shredded extra sharp cheddar cheese
¼ cup finely grated Parmesan cheese
1 tsp. freshly ground black pepper
½ tsp. kosher salt
¼ tsp. cayenne pepper
5 Tbsp. cold unsalted butter, cubed

1. In a food processor, combine flour, cheeses, pepper, salt, and cayenne; process until combined, about 15 seconds. Add butter; pulse just until mixture is combined and looks like sandy crumbs, about 30 seconds. Drizzle in 2 Tbsp. ice-cold water; pulse just until dough comes together.

2. Transfer dough to a lightly floured surface; divide in half. Roll each into a log about 1½ inches in diameter. Wrap each log in plastic wrap; chill until firm, at least 2 hours. (Or, place in a resealable plastic bag and freeze up to 6 months)

3. Preheat oven to 350ºF. Line two baking sheets with parchment paper. Using a sharp knife, slice chilled logs into ¼-inch-thick slices. Place on baking sheets about ½ inch apart. Bake until golden brown, 20 to 22 minutes.

4. Let shortbread cool on baking sheets 5 minutes, then transfer to wire racks to cool completely. Makes about 2 dozen.

[how to store] Keep in an airtight container at room temperature overnight, then refrigerate up to 1 week.