1. Adjust oven rack to lower-middle position; heat oven to 450°F. Whisk flour, half of cheese, baking powder, baking soda, salt, black pepper, and cayenne together in large bowl.

2. Add shortening to flour mixture; break up chunks with fingertips until only small, pea-sized pieces remain. Working in batches of five or six at a time, drop butter slices into flour mixture and toss to coat; pick up each slice of butter and press between floured fingertips into flat, flaky, nickel-sized pieces. Repeat until all butter is incorporated; toss mixture lightly to combine. Freeze flour mixture (with bowl) until thoroughly chilled, about 15 minutes (or refrigerate about 30 minutes).

3. Spray 24-inch-square area of work surface with nonstick cooking spray; spread spray evenly across surface with kitchen towel or paper towel. Sprinkle 1/3 cup of extra flour across sprayed area; gently spread flour across work surface with palm to form thin, even coating. Add all but 2 tablespoons of buttermilk to flour mixture; stir briskly with fork until ball forms and no dry bits of flour are visible, adding remaining buttermilk as needed (dough will be sticky and shaggy, but should clear sides of bowl). With rubber spatula, transfer dough onto center of prepared work surface, dust lightly with flour, and with floured hands, bring dough together into cohesive ball.

4. Pat dough into approximate 10-inch-square; roll into 18 x 14-inch rectangle approximately 1/4-inch-thick, dusting dough and rolling pin lightly with additional flour as needed to prevent sticking. Using bench scraper or thin metal spatula, fold dough into thirds, brushing any excess flour from surface; lift short end of dough and fold in thirds again to form approximate 6 x 4-inch rectangle. Rotate dough 90 degrees dusting work surface underneath with additional flour; roll and fold dough again, continuing to dust lightly with flour as needed.

5. Roll dough into 10-inch-square about 1/2-inch-thick; flip dough over and cut nine 3-inch rounds with floured biscuit cutter, dipping cutter back into flour between each cut. Using bench scraper or thin metal spatula, carefully invert and transfer rounds to ungreased baking sheet, spacing them at least 1 inch apart. Gather dough scraps into ball; roll and fold once or twice until scraps come together to form smooth dough. Roll dough into 1/2-inch-thick round; cut 3 more 3-inch rounds and transfer to baking sheet. Discard excess dough.

6. Brush tops of rounds with melted butter, then sprinkle evenly with remaining cheese. Bake, without opening oven door, until tops are golden brown and crisp, 15 to 17 minutes. Let cool on baking sheet for 5 to 10 minutes before serving.

Makes 12 biscuits